Effect of external magnetic field on valence-electron structures of Fe and Ni in Invar, Permalloy and the other Fe–Ni alloys by using Kβ-to-Kα X-ray intensity ratios

Abstract The effect of external magnetic field on the valence-electron structures of Fe and Ni in various Fe–Ni alloy compositions was investigated by using X-ray fluorescence spectroscopy. Firstly, K β - to - K α X-ray intensity ratios of Fe and Ni in Invar ( F e 0.64 N i 0.36 ), Permalloy ( F e 0.20 N i 0.80 ) and F e x N i 1 - x ( x =0, 0.40, 0.52, 0.55, 0.61, and 1) alloys were measured without any magnetic field and under 0.5 and 1 T external magnetic fields, separately. Later, the valence-electron structures of Fe and Ni in both pure form and alloys were obtained by comparison of measured X-ray intensity ratios with the results of multi-configurations Dirac-Fock (MCDF) calculations. The results obtained for valence-electron structures of Fe and Ni in various Fe–Ni alloys were evaluated in terms of magnetic field effect, delocalization and/or charge transfer phenomena. The results have shown that valence electron structure of Fe and Ni in Fe–Ni alloys are dependent on both external magnetic field and concentration of alloy elements.