The present work envisages synthesis of magnetic nanocomposites by ion beam mixing technique using swift heavy ion irradiation of Ni-Teflon bilayer system and its magnetic characterizations. The nanocomposite is characterized by Rutherford backscattering spectrometry (RBS), transmission electron microscopy (TEM), scanning probe microscopy (SPM) and superconducting quantum interference device (S...

In this work, we present an experimental technique for obtaining highly ordered L1 FePt-oxide thin film media at moderate deposition temperatures. In most previous studies, a FePt-Oxide layer is directly deposited on a (001) textured MgO layer. By introducing a buffer layer in between the FePt-oxide layer and the MgO underlayer, we are able to substantially enhance the L1 ordering of the FePt-o...

The effect of Fe, Cu, Zr, and Ti substitution on magnetic properties of SmCo 1 : 7 magnets at temperatures up to 500 C were studied. As-milled amorphous Sm(Co,Fe,Cu,Ti–Zr)7 magnets crystallized in the TbCu7-type structure after annealing at 750 C for 2 h. A room-temperature intrinsic coercivity of around 2.5 T is obtained for compositions SmCo6 4Zr0 2Ti0 4 and SmCo6 4Fe0 1Zr0 1Ti0 4. The high c...

Ordered 20 nm Fe–Pd nanowire arrays with different compositions have been fabricated by alternating current electrodeposition into nanoporous anodic alumina. The structural and magnetic properties of the arrays were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). When Fe content is lower than 46 at.%, Fe–Pd alloy phase wit...

A custom-designed apparatus was used for the fine-tuned co-deposition of preformed Fe clusters into antiferromagnetic Cr matrices. Three series of samples with precisely defined cluster sizes, with accuracy to a few atoms, and controlled concentrations were fabricated, followed by a complete characterization of structure and magnetic performance. Relevant magnetic characteristics, reflecting th...

The geometrical optimization of aligned hard-soft permanent-magnet nanocomposites is investigated by model calculations. Considered criteria are the shapes of the soft and c-axis-aligned hard phases, the packing fraction of the soft phase, and magnetostatic interactions. Taking into account that the energy product is enhanced via the volume fraction of the soft phase, subject to maintaining coe...

To develop a full understanding of interactions in nanomagnet arrays is a persistent challenge, critically impacting their technological acceptance. This paper reports the experimental, numerical and analytical investigation of interactions in arrays of Co nanoellipses using the first-order reversal curve (FORC) technique. A mean-field analysis has revealed the physical mechanisms giving rise t...

The temperature dependence of the magnetic viscosity coefficient (Sv), the activation volume (Vact) and the coercivity (Hc) were examined for CoCrTa/Cr and CoCrPtTa/Cr thin films in the temperature range from 200 to 423 K. This experiment shows that the medium noise measured for 150 kFCI is approximately proportional to kT/Sv (=Vact X Ms) at 298K. kT/Sv and the temperature variation of coercivi...

The abstract nonlocal boundary value problem −d2u t /dt2 Au t g t , 0 < t < 1, du t /dt − Au t f t , 1 < t < 0, u 1 u −1 μ for differential equations in a Hilbert space H with the self-adjoint positive definite operator A is considered. The well-posedness of this problem in Hölder spaces with a weight is established. The coercivity inequalities for the solution of boundary value problems for el...

The ultrathin SmCo5 nanoflakes with average thickness smaller than 50 nm are prepared by a novel method of solid particle (NaCl) and surfactant co-assisted ball milling. The as-prepared nanoflakes exhibit a narrower thickness distribution of 10-50 nm and high coercivity of 23 kOe. The possible formation mechanism of nanoflakes are proposed. Temperature dependence of demagnetization curves indic...