NMR of MnAl and MnBi_1-xSb_x

Abstract

NMR studies of MnAl and MnBiSb magnetic materials are reported. Mn samples were prepared by melting, quenching and heat treating for 30 min at 500°C. Resonance lines at 200 MHz and 100 MHz in the MnAl NMR spectrum originated in ⁵⁵ Mn and ²⁷ Al, and each had a satellite line on the low frequency side. Satellite lines attributed to ⁵⁵ Mn resonance with Mn atoms in Al nearest-neighbor sites was also observed; a similar ²⁷ Al satellite line was also observed. The Mn atoms in Al sites had magnetic moments antiparallel to the regular Mn atoms, a result confirmed by neutron diffraction studies. For MnBi 1-x Sb x , ⁵⁵ Mn NMR lines were observed at around x = 0.02 but not at x = 0.05.