Pinning type coercivity has been induced in large sø50 mmd particles of Sm2Fe17N3 by irradiation with 5 GeV Pb561 ions. Mössbauer spectroscopy is used to analyze the structure of the defects and estimate their volume. Magnetization measurements indicate that the induced defects are anisotropic in shape. A model of strong pinning by cylindrical defects is employed to deduce a defect radius of or...

This paper presents computable lower bounds of the penalty parameters for stable and convergent symmetric interior penalty Galerkin methods. In particular, we derive the explicit dependence of the coercivity constants with respect to the polynomial degree and the angles of the mesh elements. Numerical examples in all dimensions and for different polynomial degrees are presented. We show the num...

(Fe0 7Co0 3)1 N (or FeCoN) alloy single layers and FeCoN film sandwiched between two very thin (5 nm) permalloy layers have been synthesized by RF diode sputtering. The saturation magnetization of the as-deposited FeCoN single layers was found to be around 24.5 kG, the same as the pure Fe0 7Co0 3 alloy; and the minimum hard-axis coercivity was 5 Oe. In contrast, the sandwiched FeCoN films have ...

The influence of Cu, Ag, and Au additives on the L10 ordering, texture, and grain size of FePt thin films has been examined. Lattice parameter data indicated that Au and Ag additives tended to segregate from FePt, but Cu alloyed with FePt. FePt films with Au or Ag additive showed 1–2 kOe higher coercivity values compared to a pure FePt film after annealing at 450 °C and above for 10 min. The ad...

We report on continued measurements using an experimental model system to quantify intergranular exchange coupling in CoCrPtoxide perpendicular magnetic recording media. A thin film multi-layered structure comprising a high coercivity CoPt unicrystal layer separated from a low coercivity CoPt layer by a thin oxide interlayer is used to model the vertically aligned grains separated by oxide boun...

Various coercivity conditions appear in the literature in order to guarantee solutions for the Variational Inequality Problem. We show that these conditions are equivalent to each other and that they are not only sufficient, but also necessary for the set of solutions to be non-empty and bounded.

In this paper, we consider strong form of a vector equilibrium problem and establish some existence results for solutions of such problem in the setting of topological vector spaces. We provide several coercivity conditions under which strong vector equilibrium problem has a solution. Our results generalize and extend the results of Bianchi and Pini [Coercivity conditions for equilibrium proble...

The paper reports correlation between processing, structural and magnetic properties of cobalt nanoparticles dispersed in an insulating oxide matrix. High-temperature, chemical decomposition approach was utilized to achieve highly-dispersed, ultra-fine cobalt nanoparticles in silica matrix. Synthesis parameters such as precursor to passivating agent ratio were designed to control the metal-to-o...