Chemical and structural heterogeneity and the resulting interaction of coexisting phases can lead to extraordinary behaviours in oxides, as observed in piezoelectric materials at morphotropic phase boundaries and relaxor ferroelectrics. However, such phenomena are rare in metallic alloys. Here we show that, by tuning the presence of structural heterogeneity in textured Co(1-x)Fe(x) thin films, ...

We present a new approach to magnetostriction that is formulated to describe materials with large magnetostriction. The main idea of the theory is to derive precisely from lattice considerations the potential wells of the anisotropy energy. The theory exhibits frustration in the sense explored by the authors in the rigid case (James and Kinderlehrer [1990]), with fine domains modeled by minimiz...

Magnetostriction of ferromagnetic materials describes the change of their shape or dimension in response to the reorientation of magnetization under the influence of external magnetic field. Fe(100-x)Ga(x) binary alloys (Galfenol) have large magnetostriction and excellent ductility; and they are very promising rare-earth free materials for applications in sensors, actuators, energy-harvesters a...

The tetragonal magnetostriction constant, (3/2)λ100, of Fe–Si single crystals was measured and was found to be structure dependent. Similar to that of Fe–Ge single crystals, (3/2)λ100 is positive in the single phase A2 regime, becomes negative in the single phase D03 regime, and changes from positive to negative between the two regimes. Short-range order in the A2 regime decreases the magnetost...

Effects of B and Cr additions on magnetostriction and the mechanical properties of polycrystalline Fe83Ga17 alloy were investigated. Small addition of B increased magnetostriction of Fe83Ga17 alloy slightly, and improved the room temperature ductility and tensile strength significantly. The elongation and tensile strength of the (Fe83Ga17)99B1 alloy increased to 3.56% and 548MPa compared with t...

Title of dissertation: MAGNETIC AND STRUCTURAL CHARACTERIZATION OF Fe–Ga USING KERR MICROSCOPY AND NEUTRON SCATTERING Chaitanya Mudivarthi, Doctor of Philosophy, 2010 Dissertation directed by: Professor Alison B. Flatau and Professor Manfred Wuttig Dept. of Materials Science and Engineering Fe–Ga alloys belong to a class of smart materials called magnetostrictive materials. Magnetostrictive mat...

Using the highly precise full potential linearized augmented plane wave method, the phase stability, magnetism, and magnetostriction of Fe3Ga alloys were investigated. The magnetostrictive coefficients strongly depend on the atomic arrangement. The B2-like structure, although it is unstable in the small unit cell chosen here, appears to play a crucial rule for the large positive magnetostrictio...

Tb-Fe-B alloys have been melt spun and data obtained for the room temperature magnetisation and magnetostriction as functions of applied field and composition. Small additions of La (w 5 at. %) leave the magnetisation unchanged but substantially reduce the magnetostriction. Results are compared with sputtered binary metallic Tb/Fe alloys.

Magnetostriction curves with (111) textured polycrystalline Co/Pd multilayers, as deposited or submitted to ArS ion implantation or thermal annealing, are presented and discussed. Both treatments, while promoting intermixing among CO and Pd atoms, induce an increase in the saturation magnetostriction values. The evolution of the engineering curves, however, are different due to different struct...

The results of magnetostriction constant A, of multilayer Ni-Ag films are reported. The measurements have been performed at room temperature using strain modulated ferromagnetic resonance method. The magnetostriction constant As depends linearly on the inverse Ni layer thickness. This effect is suggested to be due to the reduced local symmetry in interfaces.