Abstract: The morphotropic phase boundary (MPB) recently has attracted constant interest in ferromagnetic systems for obtaining enhanced large magnetoelastic response. In the present study, structural and magnetoelastic properties of MPB involved ferromagnetic Tb1-xGdxFe2 (0≤x≤1) system has been investigated. The change of easy magnetic direction from to with increasing x up MPB composition of x=0.9 is detected by step-scanned [440] synchrotron X-ray diffraction reflections. The Gd substitution for Tb changes the composition for the anisotropy compensation near MPB composition of x=0.9, which was confirmed by the analysis of detailed scanned XRD, magnetization curves and the calculation of the first anisotropy constant K1. The spin configuration diagram accompanied with different crystal structures for Tb1-xGdxFe2 was designed. The calculated first anisotropy constant K1 shows a minimum value at MPB composition of x=0.9. In addition, the large ratio between magnetostriction, and the absolute values of the first anisotropy constant │λS∕K1│ appears at MPB composition, which makes it a potential material for magnetostrictive application. Based on experimental results, a theoretically approach was also proposed to signify that the facilitated magnetization rotation and enhanced magnetoelastic effect near MPB composition are a consequence of the anisotropic flattening of free energy of ferromagnetic crystal. Our work specifies the universal existence of MPB in ferromagnetic materials which is important for substantial improvement of magnetic and magnetostrictive properties and may provide a new route to develop advanced functional materials.
Abstract: The effect of a chiral bianisotropic substrate on the
complex resonant frequency of a rectangular microstrip resonator has
been studied on the basis of the integral equation formulation. The
analysis is based on numerical resolution of the integral equation
using Galerkin procedure for moment method in the spectral domain.
This work aim first to study the effect of the chirality of a
bianisotopic substrate upon the resonant frequency and the half
power bandwidth, second the effect of a magnetic anisotropy via an
asymptotic approach for very weak substrate upon the resonant
frequency and the half power bandwidth has been investigated. The
obtained results are compared with previously published work [11-9],
they were in good agreement.