Nanomaterials

Research

13 pages, 3490 KiB

Open AccessArticle

Efficiency of Magnetostatic Protection Using Nanostructured Permalloy Shielding Coatings Depending on Their Microstructure

by Tatiana Zubar, Sergey Grabchikov, Anna Kotelnikova, Egor Kaniukov, Maksim Kutuzau, Karin Leistner, Kornelius Nielsch, Tatiana Vershinina, Daria Tishkevich, Oleg Kanafyev, Artem Kozlovskiy, Maxim Zdorovets, Valery Fedosyuk and Alex Trukhanov

Nanomaterials 2021, 11(3), 634; https://doi.org/10.3390/nano11030634 - 4 Mar 2021

Cited by 11 | Viewed by 2798

Abstract

The effect of microstructure on the efficiency of shielding or shunting of the magnetic flux by permalloy shields was investigated in the present work. For this purpose, the FeNi shielding coatings with different grain structures were obtained using stationary and pulsed electrodeposition. The [...] Read more.

The effect of microstructure on the efficiency of shielding or shunting of the magnetic flux by permalloy shields was investigated in the present work. For this purpose, the FeNi shielding coatings with different grain structures were obtained using stationary and pulsed electrodeposition. The coatings’ composition, crystal structure, surface microstructure, magnetic domain structure, and shielding efficiency were studied. It has been shown that coatings with 0.2–0.6 µm grains have a disordered domain structure. Consequently, a higher value of the shielding efficiency was achieved, but the working range was too limited. The reason for this is probably the hindered movement of the domain boundaries. Samples with nanosized grains have an ordered two-domain magnetic structure with a permissible partial transition to a superparamagnetic state in regions with a grain size of less than 100 nm. The ordered magnetic structure, the small size of the domain, and the coexistence of ferromagnetic and superparamagnetic regions, although they reduce the maximum value of the shielding efficiency, significantly expand the working range in the nanostructured permalloy shielding coatings. As a result, a dependence between the grain and domain structure and the efficiency of magnetostatic shielding was found. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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15 pages, 4824 KiB

Open AccessArticle

Impact of Tm³⁺ and Tb³⁺ Rare Earth Cations Substitution on the Structure and Magnetic Parameters of Co-Ni Nanospinel Ferrite

by Munirah A. Almessiere, Yassine Slimani, İsmail A. Auwal, Sagar E. Shirsath, Ayyar Manikandan, Abdulhadi Baykal, Bekir Özçelik, İsmail Ercan, Sergei V. Trukhanov, Denis A. Vinnik and Alex V. Trukhanov

Nanomaterials 2020, 10(12), 2384; https://doi.org/10.3390/nano10122384 - 29 Nov 2020

Cited by 53 | Viewed by 3556

Abstract

Tm-Tb co-substituted Co-Ni nanospinel ferrites (NSFs) as (Co_0.5Ni_0.5) [Tm_xTb_xFe_2−2x]O₄ (x = 0.00–0.05) NSFs were attained via the ultrasound irradiation technique. The phase identification and morphologies of the NSFs were explored using X-rays [...] Read more.

Tm-Tb co-substituted Co-Ni nanospinel ferrites (NSFs) as (Co_0.5Ni_0.5) [Tm_xTb_xFe_2−2x]O₄ (x = 0.00–0.05) NSFs were attained via the ultrasound irradiation technique. The phase identification and morphologies of the NSFs were explored using X-rays diffraction (XRD), selected area electron diffraction (SAED), and transmission and scanning electronic microscopes (TEM and SEM). The magnetization measurements against the applied magnetic field (M-H) were made at 300 and 10 K with a vibrating sample magnetometer (VSM). The various prepared nanoparticles revealed a ferrimagnetic character at both 300 and 10 K. The saturation magnetization (M_s), the remanence (M_r), and magneton number (

n_{B}

) were found to decrease upon the Tb-Tm substitution effect. On the other hand, the coercivity (H_c) was found to diminish with increasing x up to 0.03 and then begins to increase with further rising Tb-Tm content. The H_c values are in the range of 346.7–441.7 Oe at 300 K to 4044.4–5378.7 Oe at 10 K. The variations in magnetic parameters were described based on redistribution of cations, crystallites and/or grains size, canting effects, surface spins effects, super-exchange interaction strength, etc. The observed magnetic results indicated that the synthesized (Co_0.5Ni_0.5)[Tm_xTb_xFe_2−x]O₄ NSFs could be considered as promising candidates to be used for room temperature magnetic applications and magnetic recording media. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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18 pages, 7022 KiB

Open AccessArticle

Functional Sr_0.5Ba_0.5Sm_0.02Fe_11.98O₄/x(Ni_0.8Zn_0.2Fe₂O₄) Hard–Soft Ferrite Nanocomposites: Structure, Magnetic and Microwave Properties

by Norah A. Algarou, Yassine Slimani, Munirah A. Almessiere, Ali Sadaqat, Alex V. Trukhanov, Mohammad A. Gondal, Abbas S. Hakeem, Sergei V. Trukhanov, Maksim G. Vakhitov, Denis S. Klygach, Ayyar Manikandan and Abdulhadi Baykal

Nanomaterials 2020, 10(11), 2134; https://doi.org/10.3390/nano10112134 - 27 Oct 2020

Cited by 78 | Viewed by 3123

Abstract

This paper reports the correlation between the composition of the functional Sr_0.5Ba_0.5Sm_0.02Fe_11.98O₁₉/x(Ni_0.8Zn_0.2Fe₂O₄) hard–soft nanocomposites (SrBaSmFe/x(NiZnFe) NCs), where 0.0 ≤ x ≤ [...] Read more.

This paper reports the correlation between the composition of the functional Sr_0.5Ba_0.5Sm_0.02Fe_11.98O₁₉/x(Ni_0.8Zn_0.2Fe₂O₄) hard–soft nanocomposites (SrBaSmFe/x(NiZnFe) NCs), where 0.0 ≤ x ≤ 3.0, and their structural features, magnetic, and microwave properties. SrBaSmFe/x(NiZnFe) hard/soft ferrite NCs are produced using the one-pot citrate combustion method. According to the XRD analysis, all samples showed the co-existence of both SrBaSmFe and NiZnFe phases in different ratios. Magnetic properties are measured in a wide range of magnetic fields and temperatures (10 and 300 K) and correlated well with the composition of the investigated samples. The microwave properties (frequency dispersions of the magnetic permeability, and electrical permittivity) are discussed by using the co-axial method in the frequency range of 0.7–18 GHz. Non-linear dependences of the main microwave features were observed with varying of composition. The microwave behavior correlated well with the composite theory. These results could be used in practice for developing antenna materials. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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14 pages, 5010 KiB

Open AccessArticle

Magnetite-Arginine Nanoparticles as a Multifunctional Biomedical Tool

by Victoria E. Reichel, Jasmin Matuszak, Klaas Bente, Tobias Heil, Alexander Kraupner, Silvio Dutz, Iwona Cicha and Damien Faivre

Nanomaterials 2020, 10(10), 2014; https://doi.org/10.3390/nano10102014 - 13 Oct 2020

Cited by 8 | Viewed by 3190

Abstract

Iron oxide nanoparticles are a promising platform for biomedical applications, both in terms of diagnostics and therapeutics. In addition, arginine-rich polypeptides are known to penetrate across cell membranes. Here, we thus introduce a system based on magnetite nanoparticles and the polypeptide poly-l [...] Read more.

Iron oxide nanoparticles are a promising platform for biomedical applications, both in terms of diagnostics and therapeutics. In addition, arginine-rich polypeptides are known to penetrate across cell membranes. Here, we thus introduce a system based on magnetite nanoparticles and the polypeptide poly-l-arginine (polyR-Fe₃O₄). We show that the hybrid nanoparticles exhibit a low cytotoxicity that is comparable to Resovist^®, a commercially available drug. PolyR-Fe₃O₄ particles perform very well in diagnostic applications, such as magnetic particle imaging (1.7 and 1.35 higher signal respectively for the 3rd and 11th harmonic when compared to Resovist^®), or as contrast agents for magnetic resonance imaging (R2/R1 ratio of 17 as compared to 11 at 0.94 T for Resovist^®). Moreover, these novel particles can also be used for therapeutic purposes such as hyperthermia, achieving a specific heating power ratio of 208 W/g as compared to 83 W/g for Feridex^®, another commercially available product. Therefore, we envision such materials to play a role in the future theranostic applications, where the arginine ability to deliver cargo into the cell can be coupled to the magnetite imaging properties and cancer fighting activity. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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12 pages, 2368 KiB

Open AccessArticle

An Improved Method for Estimating Core Size Distributions of Magnetic Nanoparticles via Magnetization Harmonics

by Yi Sun, Na Ye, Dandan Wang, Zhongzhou Du, Shi Bai and Takashi Yoshida

Nanomaterials 2020, 10(9), 1623; https://doi.org/10.3390/nano10091623 - 19 Aug 2020

Cited by 7 | Viewed by 2258

Abstract

The core size distribution is an important physical characteristic of magnetic nanoparticles (MNPs) because it seriously affects biomedical and biological applications. In this study, we proposed an improved method for estimating the distributions, which optimizes the excitation frequency based on AC susceptibility to [...] Read more.

The core size distribution is an important physical characteristic of magnetic nanoparticles (MNPs) because it seriously affects biomedical and biological applications. In this study, we proposed an improved method for estimating the distributions, which optimizes the excitation frequency based on AC susceptibility to avoid the effects of Brownian relaxation. Moreover, the first, third, and fifth magnetization harmonics under different excitation field strengths are used for estimating core size distributions to avoid measuring higher harmonics. The experiment results show that the improved AC harmonic method can accurately and quickly estimate the distribution of large core sizes compared with the method of static magnetization (M–H) curves, which is a competitive advantage in MNP immunoassays. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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9 pages, 2430 KiB

Open AccessArticle

Investigation of Local Conduction Mechanisms in Ca and Ti-Doped BiFeO₃ Using Scanning Probe Microscopy Approach

by Maxim S. Ivanov, Vladimir A. Khomchenko, Maxim V. Silibin, Dmitry V. Karpinsky, Carsten Blawert, Maria Serdechnova and José A. Paixão

Nanomaterials 2020, 10(5), 940; https://doi.org/10.3390/nano10050940 - 14 May 2020

Viewed by 2851

Abstract

In this work we demonstrate the role of grain boundaries and domain walls in the local transport properties of n- and p-doped bismuth ferrites, including the influence of these singularities on the space charge imbalance of the energy band structure. This is mainly [...] Read more.

In this work we demonstrate the role of grain boundaries and domain walls in the local transport properties of n- and p-doped bismuth ferrites, including the influence of these singularities on the space charge imbalance of the energy band structure. This is mainly due to the charge accumulation at domain walls, which is recognized as the main mechanism responsible for the electrical conductivity in polar thin films and single crystals, while there is an obvious gap in the understanding of the precise mechanism of conductivity in ferroelectric ceramics. The conductivity of the Bi_0.95Ca_0.05Fe_1−xTi_xO_3−δ (x = 0, 0.05, 0.1; δ = (0.05 − x)/2) samples was studied using a scanning probe microscopy approach at the nanoscale level as a function of bias voltage and chemical composition. The obtained results reveal a distinct correlation between electrical properties and the type of charged defects when the anion-deficient (x = 0) compound exhibits a three order of magnitude increase in conductivity as compared with the charge-balanced (x = 0.05) and cation-deficient (x = 0.1) samples, which is well described within the band diagram representation. The data provide an approach to control the transport properties of multiferroic bismuth ferrites through aliovalent chemical substitution. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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18 pages, 6379 KiB

Open AccessArticle

Impacts of Sol-Gel Auto-Combustion and Ultrasonication Approaches on Structural, Magnetic, and Optical Properties of Sm-Tm Co-Substituted Sr_0.5Ba_0.5Fe₁₂O₁₉ Nanohexaferrites: Comparative Study

by Yassine Slimani, Munirah Abdullah Almessiere, Sadik Güner, Umran Kurtan and Abdulhadi Baykal

Nanomaterials 2020, 10(2), 272; https://doi.org/10.3390/nano10020272 - 6 Feb 2020

Cited by 21 | Viewed by 3556

Abstract

In this paper, we introduced a comparative study of Sm-Tm-substituted Sr-Ba nanohexaferrites (NHFs), Sr_0.5Ba_0.5Tm_xSm_xFe_12−2xO₁₉ with x = 0.00–0.05, manufactured via both citrate sol-gel auto-combustion and ultrasonication approaches. The phase formation of [...] Read more.

In this paper, we introduced a comparative study of Sm-Tm-substituted Sr-Ba nanohexaferrites (NHFs), Sr_0.5Ba_0.5Tm_xSm_xFe_12−2xO₁₉ with x = 0.00–0.05, manufactured via both citrate sol-gel auto-combustion and ultrasonication approaches. The phase formation of M-type hexaferrite (HF) for both compositions was confirmed by X-ray diffraction (XRD) powder pattern, Fourier-transform infrared (FT-IR) spectra, scanning and transmission electron microscopy (SEM and TEM) micrographs, energy dispersive X-ray (EDX) spectra, and elemental mappings. The magnetic properties at room temperature (RT) and low temperature (T = 10 K) were also investigated. M-H loops revealed ferrimagnetic nature for various prepared nanohexaferrites via sol-gel and ultrasonication routes. The M_s (saturation magnetization) and M_r (remanence) values increased with increasing Tm-Sm substituting contents. M_s and M_r reached their maximum values at x = 0.04 in the case of samples prepared using the sol-gel technique and at x = 0.03 for those prepared via ultrasonication route. M-H loops were very broad in samples prepared via ultrasonication route in comparison to those produced by means of the sol-gel approach, implying that the products synthesized via ultrasonication route have greater values of coercivity (H_c). The variations in H_c values with respect to Tm-Sm substitutions were governed by the evolutions in the magneto-crystalline anisotropy. Diffuse reflectance spectra (DRS) were employed to estimate the direct band gap of pristine and co-substituted Sr_0.5Ba_0.5Fe₁₂O₁₉ hexaferrites. Optical energy band gaps (E_g) of pristine samples were significantly tuned by co-substitution of Tm³⁺ and Sm³⁺ ions. E_g values of the Sr_0.5Ba_0.5Fe₁₂O₁₉ sample, which was synthesized using the sol-gel method, decreased almost linearly from 1.75 to 1.45 eV by increasing co-doped ion content. However, we observed a sharp drop from 1.85 eV to an average of 1.50 eV for the samples, which were synthesized using the ultrasonication approach. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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8 pages, 3075 KiB

Open AccessArticle

High Entropy Oxide Phases with Perovskite Structure

by Denis A. Vinnik, Evgeny A. Trofimov, Vladimir E. Zhivulin, Svetlana A. Gudkova, Olga V. Zaitseva, Dmitry A. Zherebtsov, Andrey Yu. Starikov, Darya P. Sherstyuk, Abdulkarim A. Amirov, Alexandr V. Kalgin, Sergey V. Trukhanov and Fedor V. Podgornov

Nanomaterials 2020, 10(2), 268; https://doi.org/10.3390/nano10020268 - 5 Feb 2020

Cited by 47 | Viewed by 7030

Abstract

The possibility of the formation of high entropy single-phase perovskites using solid-state sintering was investigated. The BaO–SrO–CaO–MgO–PbO–TiO₂, BaO–SrO–CaO–MgO–PbO–Fe₂O₃ and Na₂O–K₂O–CaO–La₂O₃–Ce₂O₃–TiO₂ oxide systems were investigated. The [...] Read more.

The possibility of the formation of high entropy single-phase perovskites using solid-state sintering was investigated. The BaO–SrO–CaO–MgO–PbO–TiO₂, BaO–SrO–CaO–MgO–PbO–Fe₂O₃ and Na₂O–K₂O–CaO–La₂O₃–Ce₂O₃–TiO₂ oxide systems were investigated. The optimal synthesis temperature is found between 1150 and 1400 °C, at which the microcrystalline single phase with perovskite structure was produced. The morphology, chemical composition, crystal parameters and dielectric properties were studied and compared with that of pure BaTiO₃. According to the EDX data, the single-phase product has a formula of Na_0.30K_0.07Ca_0.24La_0.18Ce_0.21TiO₃ and a cubic structure. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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10 pages, 3747 KiB

Open AccessArticle

Controlling the Transverse Magneto-Optical Kerr Effect in Cr/NiFe Bilayer Thin Films by Changing the Thicknesses of the Cr Layer

by Hisham Hashim, Mikhail Kozhaev, Pavel Kapralov, Larissa Panina, Vladimir Belotelov, Ivana Víšová, Dagmar Chvostová, Alexandr Dejneka, Ihor Shpetnyi, Vitalii Latyshev, Serhii Vorobiov and Vladimír Komanický

Nanomaterials 2020, 10(2), 256; https://doi.org/10.3390/nano10020256 - 1 Feb 2020

Cited by 5 | Viewed by 4784

Abstract

Here, we demonstrate the impact of ferromagnetic layer coating on controlling the magneto-optical response. We found that the transverse magneto-optical Kerr effect (TMOKE) signal and TMOKE hysteresis loops of Ni₈₀Fe₂₀ thin layers coated with a Cr layer show a strong [...] Read more.

Here, we demonstrate the impact of ferromagnetic layer coating on controlling the magneto-optical response. We found that the transverse magneto-optical Kerr effect (TMOKE) signal and TMOKE hysteresis loops of Ni₈₀Fe₂₀ thin layers coated with a Cr layer show a strong dependence on the thickness of the Cr layer and the incidence angle of the light. The transmission and reflection spectra were measured over a range of incidence angles and with different wavelengths so as to determine the layers’ optical parameters and to explain the TMOKE behavior. The generalized magneto-optical and ellipsometry (GMOE) model based on modified Abeles characteristic matrices was used to examine the agreement between the experimental and theoretical results. A comprehensive theoretical and experimental analysis reveals the possibility to create a TMOKE suppression/enhancement coating at specific controllable incidence angles. This has potential for applications in optical microscopy and sensors. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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20 pages, 5522 KiB

Open AccessArticle

Electrochemical Behaviour of Ti/Al₂O₃/Ni Nanocomposite Material in Artificial Physiological Solution: Prospects for Biomedical Application

by Alla Vorobjova, Daria Tishkevich, Dmitriy Shimanovich, Maxim Zdorovets, Artem Kozlovskiy, Tatiana Zubar, Denis Vinnik, Mengge Dong, Sergey Trukhanov, Alex Trukhanov and Valery Fedosyuk

Nanomaterials 2020, 10(1), 173; https://doi.org/10.3390/nano10010173 - 19 Jan 2020

Cited by 64 | Viewed by 3964

Abstract

Inorganic-based nanoelements such as nanoparticles (nanodots), nanopillars and nanowires, which have at least one dimension of 100 nm or less, have been extensively developed for biomedical applications. Furthermore, their properties can be varied by controlling such parameters as element shape, size, surface functionalization, [...] Read more.

Inorganic-based nanoelements such as nanoparticles (nanodots), nanopillars and nanowires, which have at least one dimension of 100 nm or less, have been extensively developed for biomedical applications. Furthermore, their properties can be varied by controlling such parameters as element shape, size, surface functionalization, and mutual interactions. In this study, Ni-alumina nanocomposite material was synthesized by the dc-Ni electrodeposition into a porous anodic alumina template (PAAT). The structural, morphological, and corrosion properties were studied using x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and electrochemical techniques (linear sweep voltammetry). Template technology was used to obtain Ni nanopillars (NiNPs) in the PAAT nanocomposite. Low corrosion current densities (order of 0.5 µA/cm²) were indicators of this nanocomposite adequate corrosion resistance in artificial physiological solution (0.9% NaCl). A porous anodic alumina template is barely exposed to corrosion and performs protective functions in the composite. The results may be useful for the development of new nanocomposite materials technologies for a variety of biomedical applications including catalysis and nanoelectrodes for sensing and fuel cells. They are also applicable for various therapeutic purposes including targeting, diagnosis, magnetic hyperthermia, and drug delivery. Therefore, it is an ambitious task to research the corrosion resistance of these magnetic nanostructures in simulated body fluid. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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17 pages, 8667 KiB

Open AccessArticle

Functional Magnetic Composites Based on Hexaferrites: Correlation of the Composition, Magnetic and High-Frequency Properties

by Lyudmila Yu. Matzui, Alex V. Trukhanov, Olena S. Yakovenko, Ludmila L. Vovchenko, Volodymyr V. Zagorodnii, Victor V. Oliynyk, Mykola O. Borovoy, Ekaterina L. Trukhanova, Ksenia A. Astapovich, Dmitry V. Karpinsky and Sergei V. Trukhanov

Nanomaterials 2019, 9(12), 1720; https://doi.org/10.3390/nano9121720 - 2 Dec 2019

Cited by 98 | Viewed by 3863

Abstract

The paper describes preparation features of functional composites based on ferrites, such as “Ba(Fe₁₋_xGa_x)₁₂O₁₉/epoxy,” and the results of studying their systems; namely, the correlation between structure, magnetic properties and electromagnetic absorption characteristics. We [...] Read more.

The paper describes preparation features of functional composites based on ferrites, such as “Ba(Fe₁₋_xGa_x)₁₂O₁₉/epoxy,” and the results of studying their systems; namely, the correlation between structure, magnetic properties and electromagnetic absorption characteristics. We demonstrated the strong mutual influence of the chemical compositions of magnetic fillers (Ba(Fe₁₋_xGa_x)₁₂O₁₉ 0.01 < x < 0.1 solid solutions), and the main magnetic (coercivity, magnetization, anisotropy field and the first anisotropy constant) and microwave (resonant frequency and amplitude) characteristics of functional composites with 30 wt.% of hexaferrite. The paper presents a correlation between the chemical compositions of composites and amplitude–frequency characteristics. Increase of Ga-content from x = 0 to 0.1 in Ba(Fe₁₋_xGa_x)₁₂O₁₉/epoxy composites leads to increase of the resonant frequency from 51 to 54 GHz and absorption amplitude from −1.5 to −10.5 dB/mm. The ability to control the electromagnetic properties in these types of composites opens great prospects for their practical applications due to high absorption efficiency, and lower cost in comparison with pure ceramics oxides. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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12 pages, 5522 KiB

Open AccessArticle

Synthesis of Mn_0.5Zn_0.5Sm_xEu_xFe_1.8−2xO₄ Nanoparticles via the Hydrothermal Approach Induced Anti-Cancer and Anti-Bacterial Activities

by Sultan Akhtar, Suriya Rehman, Munirah A. Almessiere, Firdos Alam Khan, Yassine Slimani and Abdulhadi Baykal

Nanomaterials 2019, 9(11), 1635; https://doi.org/10.3390/nano9111635 - 18 Nov 2019

Cited by 64 | Viewed by 3980

Abstract

Manganese metallic nanoparticles are attractive materials for various biological and medical applications. In the present study, we synthesized unique Mn_0.5Zn_0.5Sm_xEu_xFe_1.8−2xO₄ (0.01 ≤ x ≤ 0.05) nanoparticles (NPs) by using the hydrothermal approach. [...] Read more.

Manganese metallic nanoparticles are attractive materials for various biological and medical applications. In the present study, we synthesized unique Mn_0.5Zn_0.5Sm_xEu_xFe_1.8−2xO₄ (0.01 ≤ x ≤ 0.05) nanoparticles (NPs) by using the hydrothermal approach. The structure and surface morphology of the products were determined by X-ray powder diffraction (XRD), transmission electron and scanning electron microcopies (TEM and SEM), along with energy dispersive X-ray spectroscopy (EDX). We evaluated the impact of Mn_0.5Zn_0.5Sm_xEu_xFe_1.8−2xO₄ NPs on both human embryonic stem cells (HEK-293) (normal cells) and human colon carcinoma cells (HCT-116) (cancerous cells). We found that post-48 h of treatment of all products showed a significant decline in the cancer cell population as revealed by microscopically and the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium (MTT) assay. The inhibitory concentration (IC₅₀) values of the products ranged between 0.75 and 2.25 µg/mL. When tested on normal and healthy cells (HEK-293), we found that the treatment of products did not produce any effects on the normal cells, which suggests that all products selectively targeted the cancerous cells. The anti-bacterial properties of the samples were also evaluated by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays, which showed that products also inhibited the bacterial growth. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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16 pages, 5125 KiB

Open AccessArticle

Synthesis and Properties of Ferrite-Based Nanoparticles

by Kayrat K. Kadyrzhanov, Kamila Egizbek, Artem L. Kozlovskiy and Maxim V. Zdorovets

Nanomaterials 2019, 9(8), 1079; https://doi.org/10.3390/nano9081079 - 27 Jul 2019

Cited by 34 | Viewed by 4018

Abstract

The work is dedicated to the study of the structural and optical characteristics, as well as the phase transformations, of ferrite nanoparticles of CeO₂-Fe₂O₃. To characterize the results obtained, the methods of scanning and transmission microscopy, X-ray [...] Read more.

The work is dedicated to the study of the structural and optical characteristics, as well as the phase transformations, of ferrite nanoparticles of CeO₂-Fe₂O₃. To characterize the results obtained, the methods of scanning and transmission microscopy, X-ray diffraction (XRD) spectroscopy, and Mössbauer spectroscopy were applied. It was found that the initial nanoparticles are polycrystalline structures based on cerium oxide with the presence of X-ray amorphous inclusions in the structure, which are characteristic of iron oxide. The study determined the dynamics of phase and structural transformations, as well as the appearance of a magnetic texture depending on the annealing temperature. According to the Mossbauer spectroscopy data, it has been established that a rise in the annealing temperature gives rise to an ordering of the magnetic properties and a decrease in the concentration of cationic and vacancy defects in the structure. During the life test of synthesized nanoparticles as cathode materials for lithium-ion batteries, the dependences of the cathode lifetime on the phase composition of nanoparticles were established. It is established that the appearance of a magnetic component in the structure result in a growth in the resource lifetime and the number of operating cycles. The results show the prospects of using these nanoparticles as the basis for lithium-ion batteries, and the simplicity of synthesis and the ability to control phase transformations opens up the possibility of scalable production of these nanoparticles for cathode materials. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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16 pages, 6588 KiB

Open AccessArticle

Study of Magnetic Properties of Fe_100-xNi_x Nanostructures Using the Mössbauer Spectroscopy Method

by Kayrat K. Kadyrzhanov, Vyacheslav S. Rusakov, Maxim S. Fadeev, Tatyana Yu. Kiseleva, Artem L. Kozlovskiy, Inesh E. Kenzhina and Maxim V. Zdorovets

Nanomaterials 2019, 9(5), 757; https://doi.org/10.3390/nano9050757 - 17 May 2019

Cited by 19 | Viewed by 3190

Abstract

Hyperfine interactions of ⁵⁷Fe nuclei in Fe_100-xNi_x nanostructures synthesized in polymer ion-track membranes were studied by Mössbauer spectroscopy. The main part of obtained nanostructures was Fe_100-xNi_x nanotubes with bcc structure for 0 ≤ x ≤ 40, [...] Read more.

Hyperfine interactions of ⁵⁷Fe nuclei in Fe_100-xNi_x nanostructures synthesized in polymer ion-track membranes were studied by Mössbauer spectroscopy. The main part of obtained nanostructures was Fe_100-xNi_x nanotubes with bcc structure for 0 ≤ x ≤ 40, and with fcc structure for 50 ≤ x ≤ 90. The length, outside diameter and wall thickness of nanotubes were 12 μm, 400 ± 10 nm and 120 ± 5 nm respectively. For the studied nanotubes a magnetic texture is observedalong their axis. The average value of the angle between the direction of the Fe atom magnetic moment and the nanotubes axis decreases with increasing of Ni concentration for nanotubes with bcc structure from ~50° to ~40°, and with fcc structure from ~55° to ~46°. The concentration dependences of the hyperfine parameters of nanotubes Mössbauer spectra are qualitatively consistent with the data for bulk polycrystalline samples. With Ni concentration increasing the average value of the hyperfine magnetic field increases from ~328 kOe to ~335 kOe for the bcc structure and drops to ~303 kOe in the transition to the fcc structure and then decreases to ~290 kOe at x = 90. Replacing the Fe atom with the Ni atom in the nearest environment of Fe atom within nanotubes with bcc structure lead to an increase in the hyperfine magnetic field by “6–9 kOe”, and in tubes with fcc structure—to a decrease in the hyperfine magnetic field by “11–16 kOe”. The changes of the quadrupole shift and hyperfine magnetic field are linearly correlated with the coefficient −(15 ± 5)·10⁻⁴ mm/s/kOe. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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11 pages, 4341 KiB

Open AccessArticle

Extremely Polysubstituted Magnetic Material Based on Magnetoplumbite with a Hexagonal Structure: Synthesis, Structure, Properties, Prospects

by Denis A. Vinnik, Vladimir E. Zhivulin, Evgeny A. Trofimov, Andrey Y. Starikov, Dmitry A. Zherebtsov, Olga V. Zaitseva, Svetlana A. Gudkova, Sergey V. Taskaev, Denis S. Klygach, Maxim G. Vakhitov, Elena E. Sander, Darya P. Sherstyuk and Alexey V. Trukhanov

Nanomaterials 2019, 9(4), 559; https://doi.org/10.3390/nano9040559 - 6 Apr 2019

Cited by 24 | Viewed by 3848

Abstract

Crystalline high-entropy single-phase products with a magnetoplumbite structure with grains in the μm range were obtained using solid-state sintering. The synthesis temperature was up to 1400 °C. The morphology, chemical composition, crystal structure, magnetic, and electrodynamic properties were studied and compared with pure [...] Read more.

Crystalline high-entropy single-phase products with a magnetoplumbite structure with grains in the μm range were obtained using solid-state sintering. The synthesis temperature was up to 1400 °C. The morphology, chemical composition, crystal structure, magnetic, and electrodynamic properties were studied and compared with pure barium hexaferrite BaFe₁₂O₁₉ matrix. The polysubstituted high-entropy single-phase product contains five doping elements at a high concentration level. According to the EDX data, the new compound has a formula of Ba(Fe₆Ga_1.25In_1.17Ti_1.21Cr_1.22Co_1.15)O₁₉. The calculated cell parameter values were a = 5.9253(5) Å, c = 23.5257(22) Å, and V = 715.32(9) Å³. The increase in the unit cell for the substituted sample was expected due to the different ionic radius of Ti/In/Ga/Cr/Co compared with Fe³⁺. The electrodynamic measurements were performed. The dielectric and magnetic permeabilities were stable in the frequency range from 2 to 12 GHz. In this frequency range, the dielectric and magnetic losses were −0.2/0.2. Due to these electrodynamic parameters, this material can be used in the design of microwave strip devices. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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19 pages, 3262 KiB

Open AccessArticle

Fe₃O₄ Nanoparticles for Complex Targeted Delivery and Boron Neutron Capture Therapy

by Kanat Dukenbayev, Ilya V. Korolkov, Daria I. Tishkevich, Artem L. Kozlovskiy, Sergey V. Trukhanov, Yevgeniy G. Gorin, Elena E. Shumskaya, Egor Y. Kaniukov, Denis A. Vinnik, Maxim V. Zdorovets, Marina Anisovich, Alex V. Trukhanov, Daniele Tosi and Carlo Molardi

Nanomaterials 2019, 9(4), 494; https://doi.org/10.3390/nano9040494 - 31 Mar 2019

Cited by 141 | Viewed by 7512

Abstract

Magnetic Fe₃O₄ nanoparticles (NPs) and their surface modification with therapeutic substances are of great interest, especially drug delivery for cancer therapy, including boron-neutron capture therapy (BNCT). In this paper, we present the results of boron-rich compound (carborane borate) attachment to [...] Read more.

Magnetic Fe₃O₄ nanoparticles (NPs) and their surface modification with therapeutic substances are of great interest, especially drug delivery for cancer therapy, including boron-neutron capture therapy (BNCT). In this paper, we present the results of boron-rich compound (carborane borate) attachment to previously aminated by (3-aminopropyl)-trimethoxysilane (APTMS) iron oxide NPs. Fourier transform infrared spectroscopy with Attenuated total reflectance accessory (ATR-FTIR) and energy-dispersive X-ray analysis confirmed the change of the element content of NPs after modification and formation of new bonds between Fe₃O₄ NPs and the attached molecules. Transmission (TEM) and scanning electron microscopy (SEM) showed Fe₃O₄ NPs’ average size of 18.9 nm. Phase parameters were studied by powder X-ray diffraction (XRD), and the magnetic behavior of Fe₃O₄ NPs was elucidated by Mössbauer spectroscopy. The colloidal and chemical stability of NPs was studied using simulated body fluid (phosphate buffer—PBS). Modified NPs have shown excellent stability in PBS (pH = 7.4), characterized by XRD, Mössbauer spectroscopy, and dynamic light scattering (DLS). Biocompatibility was evaluated in-vitro using cultured mouse embryonic fibroblasts (MEFs). The results show us an increasing of IC₅₀ from 0.110 mg/mL for Fe₃O₄ NPs to 0.405 mg/mL for Fe₃O₄-Carborane NPs. The obtained data confirm the biocompatibility and stability of synthesized NPs and the potential to use them in BNCT. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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16 pages, 10881 KiB

Open AccessArticle

A First-Principles Study on the Multiferroic Property of Two-Dimensional BaTiO₃ (001) Ultrathin Film with Surface Ba Vacancy

by Haigen Gao, Zhenxing Yue, Yande Liu, Jun Hu and Xiong Li

Nanomaterials 2019, 9(2), 269; https://doi.org/10.3390/nano9020269 - 15 Feb 2019

Cited by 11 | Viewed by 3233

Abstract

In this work, the multiferroic property of Ba-deficient BaTiO₃ (001) ultrathin film is studied employing the first-principles approach. The BaTiO₃ (001) ultrathin film is more energetically stable and behaves as a semiconductor relative to the (111) and (101) configurations, confirmed from [...] Read more.

In this work, the multiferroic property of Ba-deficient BaTiO₃ (001) ultrathin film is studied employing the first-principles approach. The BaTiO₃ (001) ultrathin film is more energetically stable and behaves as a semiconductor relative to the (111) and (101) configurations, confirmed from the surface grand potential and electronic density of states. The electronic structures show that the O vacancy can switch the (001) film from a semi-conductor into a metal, while the Ba defect has a slight influence on the band gap, at a concentration of ~2.13%. In Ba-deficient (001) film, the spontaneous polarization pattern is changed and a spontaneous polarization parallel to the surface is observed. Furthermore, a magnetic moment is induced, and it is found to be originated from the O atoms in the supercell. Our results suggest that a strong magnetoelectric coupling occurs because the magnetic moment exhibits a 43.66% drop when the spontaneous polarization increases from 12.84 µC/cm² to 23.99 µC/cm² in the deficient BaTiO₃ with m = 2 under the bi-axial compress stress field. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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22 pages, 5709 KiB

Open AccessReview

Biosensing and Delivery of Nucleic Acids Involving Selected Well-Known and Rising Star Functional Nanomaterials

by Susana Campuzano, Maria Gamella, Verónica Serafín, María Pedrero, Paloma Yáñez-Sedeño and José Manuel Pingarrón

Nanomaterials 2019, 9(11), 1614; https://doi.org/10.3390/nano9111614 - 14 Nov 2019

Cited by 3 | Viewed by 2821

Abstract

In the last fifteen years, the nucleic acid biosensors and delivery area has seen a breakthrough due to the interrelation between the recognition of nucleic acid’s high specificity, the great sensitivity of electrochemical and optical transduction and the unprecedented opportunities imparted by nanotechnology. [...] Read more.

In the last fifteen years, the nucleic acid biosensors and delivery area has seen a breakthrough due to the interrelation between the recognition of nucleic acid’s high specificity, the great sensitivity of electrochemical and optical transduction and the unprecedented opportunities imparted by nanotechnology. Advances in this area have demonstrated that the assembly of nanoscaled materials allows the performance enhancement, particularly in terms of sensitivity and response time, of functional nucleic acids’ biosensing and delivery to a level suitable for the construction of point-of-care diagnostic tools. Consequently, this has propelled detection methods using nanomaterials to the vanguard of the biosensing and delivery research fields. This review overviews the striking advancement in functional nanomaterials’ assisted biosensing and delivery of nucleic acids. We highlight the advantages demonstrated by selected well-known and rising star functional nanomaterials (metallic, magnetic and Janus nanomaterials) focusing on the literature produced in the past five years. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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12 pages, 15977 KiB

Open AccessPerspective

Magnetic Tracking of Protein Synthesis in Microfluidic Environments—Challenges and Perspectives

by Melanie Wegener, Inga Ennen, Volker Walhorn, Dario Anselmetti, Andreas Hütten and Karl-Josef Dietz

Nanomaterials 2019, 9(4), 585; https://doi.org/10.3390/nano9040585 - 9 Apr 2019

Cited by 6 | Viewed by 4084

Abstract

A novel technique to study protein synthesis is proposed that uses magnetic nanoparticles in combination with microfluidic devices to achieve new insights into translational regulation. Cellular protein synthesis is an energy-demanding process which is tightly controlled and is dependent on environmental and developmental [...] Read more.

A novel technique to study protein synthesis is proposed that uses magnetic nanoparticles in combination with microfluidic devices to achieve new insights into translational regulation. Cellular protein synthesis is an energy-demanding process which is tightly controlled and is dependent on environmental and developmental requirements. Processivity and regulation of protein synthesis as part of the posttranslational nano-machinery has now moved back into the focus of cell biology, since it became apparent that multiple mechanisms are in place for fine-tuning of translation and conditional selection of transcripts. Recent methodological developments, such as ribosome foot printing, propel current research. Here we propose a strategy to open up a new field of labelling, separation, and analysis of specific polysomes using superparamagnetic particles following pharmacological arrest of translation during cell lysis and subsequent analysis. Translation occurs in polysomes, which are assemblies of specific transcripts, associated ribosomes, nascent polypeptides, and other factors. This supramolecular structure allows for unique approaches to selection of polysomes by targeting the specific transcript, ribosomes, or nascent polypeptides. Once labeled with functionalized superparamagnetic particles, such assemblies can be separated in microfluidic devices or magnetic ratchets and quantified. Insights into the dynamics of translation is obtained through quantifying large numbers of ribosomes along different locations of the polysome. Thus, an entire new concept for in vitro, ex vivo, and eventually single cell analysis will be realized and will allow for magnetic tracking of protein synthesis. Full article

(This article belongs to the Special Issue Functional Nanomagnetics and Magneto-Optical Nanomaterials)

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