ELECTRONIC AND MAGNETIC-PROPERTIES OF THE FERROMAGNETIC GAMMA-FE4N UNDER HIGH-PRESSURE

The effect of pressure up to 5.6 Cpa on the electronic and magnetic pr operties of gamma-Fe4N has been investigated using the Fe-57 high-pres sure Mossbauer effect technique at 300 K, We show that the decrease of the average isomer shift and the isomer shift for each Fe site with i ncreasing pressure indicates a corresponding increase of s-electron de nsity at the Fe-57 nucleus, which is mainly caused by the volume compr ession of the 4s conduction electrons and changes of charge transfer b etween atoms. The variation of the Second-order Doppler effect due to increasing pressure has been evaluated, The decrease of the average ma gnetic hyperfine field B-eff) 300 K in this pressure range results for m the decrease of the Fe local magnetic moment and Curie temperature w ith pressure, The magnetic hyperfine field (B-eff) at the corner Fe si te (Fe-I) decreases more rapidly with pressure than that at the face-c entered Fe site (Fe-II due to the contribution of the transferred hype rfine field to the pressure dependence of B-eff at Fe-I.