Magnetostriction of fcc(110) single-crystal films of Ni-Fe, Ni, and Co under rotating magnetic fields

Taiki Ohtani,Mitsuru Ohtake,Masaaki Futamotoa,Tetsuroh Kawai

doi:10.1051/epjconf/20147504011

Abstract

Ni-Fe, Ni, and Co(110) single-crystal films with uniaxial magnetic anisotropies are prepared on MgO(110) substrates by radio-frequency magnetron sputtering. The magnetostriction behavior under rotating magnetic fields is investigated. The Ni-Fe film shows waveforms consisting of a mixture of sinusoidal and triangular shapes under fields lower than 200 Oe. The peak of sinusoidal shape is observed when the field is applied along the easy magnetization axis, whereas that of triangular shape appears when the field is applied along the hard axis. With increasing the field from 200 to 300 Oe, the waveform changes to a usual sinusoidal shape. The waveform variation is related to the difference between the directions of uniaxial magnetic anisotropy and magnetization of magnetically unsaturated film. Waveforms consisting of sinusoidal and triangular shapes are also observed for the Ni and the Co films under low rotating fields. The threshold magnetic field where the shape changes to sinusoidal increases in the order of Ni-Fe < Ni < Co. The waveform is influenced by the symmetry and the strength of magnetic anisotropy.

Highlights

Soft magnetic materials have been widely used in applications such as transformers, motors, magnetic devices, etc
The films showed waveforms consisting of only triangular shape under rotating fields and the behavior was related with the wall motion of 90° magnetic domains existing in the magnetically unsaturated films
Thin films were prepared on MgO(110) substrates with the thickness of 200 Pm at 300 °C by using a radiofrequency (RF) magnetron sputtering system equipped with a reflection high-energy electron diffraction (RHEED) facility

Summary

Introduction

Soft magnetic materials have been widely used in applications such as transformers, motors, magnetic devices, etc. In order to investigate the magnetostriction behaviors of anisotropic magnetic materials, it is useful to employ well-defined epitaxial magnetic films, since the structure and the magnetic anisotropy are controlled by the crystallographic orientation of single-crystal substrate.

Results

Conclusion