Temperature dependence of L3M45M45 Auger transition in Fe1−xNix alloys

This paper reports the X-ray photoelectron spectroscopy (XPS) and X-ray excited Auger electron spectroscopy (XAES) measurements on Fe1−xNix (x = 0.4, 0.5, 0.6, 0.7, 0.9) alloys prepared by arc melting method. Valence band spectrum of Fe0.6Ni0.4 alloy exhibits a shift of about 0.15 eV to higher binding energy at 10 K compared to that at 300 K suggesting the precipitation of antiferromagnetic phase below 20 K. Ni L3M45M45 Auger spectra exhibit composition induced changes. The Ni L3M45M45 Auger spectrum of Fe0.6Ni0.4 alloy exhibits an anomalous increase of intensity in the kinetic energy range from 841 to 845.8 eV at 10 K compared to that of 300 K. Such an increase in intensity of the Auger signal also supports the precipitation of new fcc antiferromagnetic phase below 20 K. Fe L3M45M45 Auger overlaps with Ni L3M23M23 Auger transition and thus becomes complicated to analyze and obtain temperature or composition induced changes.