Effects of Fe doping on anomalous specific heat and XAFS oscillation in antiferromagnetic metal MnSi

Hiraka, Haruhiro*; Oyama, Kenji*; Kosaka, Masashi*; Matsumura, Daiju   

The specific heat of MnFeSi was measured over a wide temperature range. Aside from the lattice and electronic specific heat components, another component had a significant contribution to the specific heat at low temperatures in the case of = 0.2; however, its contribution decreased when = 1.0. It is observed that the net component was retained at temperatures significantly higher than for both . The XAFS spectra of the Mn -edge for = 0 not only indicated a smooth structure near the edge, but also an unusually small amplitude in the extended high energy region; however, these features disappeared with Fe doping. The specific heat and XAFS data were discussed interms of the charge degree of freedom or electronic inhomogeneity.