Rauf S. Iskhakov

Bio: Rauf S. Iskhakov is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Magnetization & Magnetic anisotropy. The author has an hindex of 18, co-authored 151 publications receiving 1006 citations. Previous affiliations of Rauf S. Iskhakov include Siberian State Aerospace University & Siberian Federal University.

Magnetic microstructure of amorphous, nanocrystalline, and nanophase ferromagnets

Abstract: The magnetic microstructure of nanostructured ferromagnets is represented by an ensemble of stochastic magnetic domains—regions with dimensions of the length of magnetic orientation coherency. It is shown that the curves displaying the approach of magnetization to saturation make it possible to determine the dimension of the element of the micromagnetic structure, i.e., the size of the stochastic domain and the constant of the effective anisotropy in this element, the size of the element of the nanostructure and the constant its local anisotropy, as well as the dimensionality of the exchange-coupled ferromagnetic nanoparticles.

Magnetic properties of Fe 3 C ferromagnetic nanoparticles encapsulated in carbon nanotubes

Abstract: The low-temperature dependences of magnetic characteristics (namely, the coercive force H c , the remanent magnetization M r , local magnetic anisotropy fields H a, and the saturation magnetization M s ) determined from the irreversible and reversible parts of the magnetization curves for Fe3C ferromagnetic nanoparticles encapsulated in carbon nanotubes are investigated experimentally The behavior of the temperature dependences of the coercive force H c (T) and the remanent magnetization M r (T) indicates a single-domain structure of the particles under study and makes it possible to estimate their blocking temperature T B = 420–450 K It is found that the saturation magnetization M s and the local magnetic anisotropy field H a vary with temperature as ∼T 5/2

Mössbauer study of bacterial ferrihydrite

Abstract: Mossbauer measurements reveal four inequivalent Fe sites in ferrihydrite produced by Klebsiella oxytoca. The origin of these sites can be understood in terms of two nanosized structural regions in the bacterium and a certain ordering of bilayers and single layers of Fe-occupied octahedra.

Review and prospects of magnonic crystals and devices with reprogrammable band structure

Abstract: Research efforts addressing spin waves (magnons) in micro- and nanostructured ferromagnetic materials have increased tremendously in recent years. Corresponding experimental and theoretical work in magnonics faces significant challenges in that spin-wave dispersion relations are highly anisotropic and different magnetic states might be realized via, for example, the magnetic field history. At the same time, these features offer novel opportunities for wave control in solids going beyond photonics and plasmonics. In this topical review we address materials with a periodic modulation of magnetic parameters that give rise to artificially tailored band structures and allow unprecedented control of spin waves. In particular, we discuss recent achievements and perspectives of reconfigurable magnonic devices for which band structures can be reprogrammed during operation. Such characteristics might be useful for multifunctional microwave and logic devices operating over a broad frequency regime on either the macro- or nanoscale.

Magnetism in ultrathin film structures

Abstract: In this paper, we review some of the key concepts in ultrathin film magnetism which underpin nanomagnetism. We survey the results of recent experimental and theoretical studies of well characterized epitaxial structures based on Fe, Co and Ni to illustrate how intrinsic fundamental properties such as the magnetic exchange interactions, magnetic moment and magnetic anisotropies change markedly in ultrathin films as compared with their bulk counterparts, and to emphasize the role of atomic scale structure, strain and crystallinity in determining the magnetic properties. After introducing the key length scales in magnetism, we describe the 2D magnetic phase transition and survey studies of the thickness dependent Curie temperature and the critical exponents which characterize the paramagnetic–ferromagnetic phase transition. We next discuss recent experimental and theoretical results on the determination of the exchange constant, followed by an overview of measurements of the magnetic moment in the elemental 3d transition metal thin films in the various crystal phases that have been successfully stabilized, thereby illustrating the sensitivity of the magnetic moment to the local symmetry and to the atomic environment. Finally, we discuss briefly the magnetic anisotropies of Fe, Co and Ni in the fcc crystalline phase, to emphasize the role of structure and the details of the interface in influencing the magnetic properties. The dramatic effect that adsorbates can have on the magnetic anisotropies of thin magnetic films is also discussed. Our survey demonstrates that the fundamental properties, namely, the magnetic moment and magnetic anisotropies of ultrathin films have dramatically different behaviour compared with those of the bulk while the comparable size of the structural and magnetic contributions to the total energy of ultrathin structures results in an exquisitely sensitive dependence of the magnetic properties on the film structure.

Nanotoxicology of Metal Oxide Nanoparticles

Abstract: This review discusses recent advances in the synthesis, characterization and toxicity of metal oxide nanoparticles obtained mainly through biogenic (green) processes. The in vitro and in vivo toxicities of these oxides are discussed including a consideration of the factors important for safe use of these nanomaterials. The toxicities of different metal oxide nanoparticles are compared. The importance of biogenic synthesized metal oxide nanoparticles has been increasing in recent years; however, more studies aimed at better characterizing the potent toxicity of these nanoparticles are still necessary for nanosafely considerations and environmental perspectives. In this context, this review aims to inspire new research in the design of green approaches to obtain metal oxide nanoparticles for biomedical and technological applications and to highlight the critical need to fully investigate the nanotoxicity of these particles.