Investigation on the magnetic and Mossbauer spectroscopy of Fe-57 doped LiMnPO4

The Fe-57 doped LiMnPO4 cathode with potential applications in Li-ion batteries was prepared by solid-state reaction. The magnetic susceptibility ordered antiferromagnetically at Neel temperature (T-N = 34 K). The spin reorientation temperature (T-S) and effective moment were determined to be 8 K and 5.78 mu(B). We obtained the Mossbauer spectra at various temperatures and fitted the spectra below T-N to eight absorption lines. The behavior of the magnetic hyperfine field and the quadrupole splitting change with increasing temperature above T-S indicates that the quenched orbital angular moment is due to a strong crystal field at the Mn(Fe)O-6 site.