Computational micromagnetics plays an important role in design and control of magnetostrictive actuators. A systematic approach to calculate magnetic dynamics and magnetostriction is presented. A finite difference method is developed to solve the coupled Landau-Lifshitz-Gilbert(LLG) equation for dynamics of magnetization and a one dimensional elastic motion equation. The effective field in the ...

Textured polycrystalline Fe-Ga alloys exhibit magnetostrictive strains of 100 ppm or greater and may function as a mechanically robust actuator/sensing material. Current efforts seek to combine the 300+ ppm magnetostrictive strain performance of [100] oriented single crystals with the mechanical properties of polycrystalline forms. One approach to combining these properties is to control the cr...

In this work, the structural and magnetic properties of ingot and melt-spun Pr3Fe24.75Co2.75Ti1.5 compounds have been investigated. The structural characterization of the compounds, by X-ray powder diffraction, is evidenced for a monoclinic Nd3(Fe,Ti)29-type structure (A2/m space group). A 2-type FOMP have been observed in the magnetic AC susceptibility curves of the ingot and melt-spun compoun...

During the manufacturing process and use of ferromagnetic sheets, operations such as rolling, cutting, and tightening induce anisotropy that changes the material's behavior. Consequently for more accuracy in magnetization and magnetostriction calculations in electric devices such as transformers, anisotropic effects should be considered. In the following sections, we give an overview of a macro...

We exploit magnetostriction in polydisperse ferrofluids in order to generate nonlinear responses and apply a thermodynamical method to derive the desired nonlinear magnetic susceptibility. For an ideal gas, this method has been demonstrated to be in excellent agreement with a statistical method. In the presence of a sinusoidal ac magnetic field, the magnetization of the polydisperse ferrofluid ...

In the scientific description of unconventional transport properties of oxides (spin-dependent transport, superconductivity etc.), the spin-state degree of freedom plays a fundamental role. Because of this, temperature- or magnetic field-induced spin-state transitions are in the focus of solid-state physics. Cobaltites, e.g. LaCoO3, are prominent examples showing these spin transitions. However...

The contribution to the magnetic uniaxial perpendicular anisotropy which arises from substrate constraint through magnetostrictive effects has been measured in Ni-Fe and Ni -Co thin films evaporated on substrates at room temperature. This was accomplished by measuring the perpendicular anisotropy before and after removal of the film from the substrate. Data are given for the f cc crystal struct...

Reexamination of the microscopic couplings of the quasi one–dimensional antiferromagnet CuGeO 3 Abstract Experimental data for the magnetic susceptibility and magnetostriction of CuGeO 3 are analyzed within a one-dimensional antiferromagnetic model with nearest (J 1) and next-nearest neighbour interactions (J 2). We show that the ratio of the exchange constants in the antiferromagnetic chains o...

Uniaxial stress-strain measurements were performed on polycrystalline Tb76Dy24 alloys which exhibit ‘‘giant magnetostriction’’ at cryogenic temperatures. The Young’s moduli were reduced by up to a factor of five at 77 K, in comparison to their values at 300 K. We attribute this reduction to a mechanical compliance from domain rotation. Large mechanical hysteresis is also found in nominally elas...

Multiferroic composite materials, consisting of coupled ferromagnetic and piezoelectric phases, are of great importance in the drive towards creating faster, smaller and more energy efficient devices for information and communications technologies. Such devices require thin ferromagnetic films with large magnetostriction and narrow microwave resonance linewidths. Both properties are often degra...