Noncollinear Spin Structure in Fe-Ni Invar Alloy Probed by Magnetic EXAFS at High Pressure

作者：Matsumoto Ken^*; Maruyama Hiroshi; Ishimatsu Naoki; Kawamura Naomi; Mizumaki Masaichiro; Irifune Tetsuo; Sumiya Hitoshi

来源：Journal of the Physical Society of Japan, 2011, 80(2): 023709.

DOI：10.1143/JPSJ.80.023709

• magnetic EXAFS
• XMCD
• EXAFS
• Fe-Ni Invar alloy
• noncollinear spin structure
• high pressure

To examine theoretical models of the Invar effect, X-ray magnetic circular dichroism and magnetic extended X-ray absorption fine structure (MEXAFS) measurements are performed under high pressures at the Fe and Ni K-edges in 35.4at.% Ni-Fe alloy. An oscillatory MEXAFS signal is observed up to 6 GPa. Its amplitude significantly decreases with increasing pressure. The magnetic component of the radial distribution function, obtained by taking the Fourier transform, shows a different reduction in the ferromagnetic correlations of Fe and Ni absorbing atoms. The present results are favorable to the noncollinear spin structure picture rather than the Fe 2 gamma-state model.

• 出版日期2011-2