Studies on Crystallographic and Mossbauer Spectra of the LiFe_0.9Mn_0.1PO₄

Abstract

The olivine structured LiFe 0.9 Mn 0.1 PO 4 material was prepared by solid state method, and was analyzed by x-ray diffractometer (XRD), superconducting quantum interference devices (SQUID) and Mössbauer spectroscopy. The crystal structure of LiFe 0.9 Mn 0.1 PO 4 was determined to be orthorhombic (space group: Pnma) by Rietveld refinement method. The value of Néel temperature (T N ) for LiFe 0.9 Mn 0.1 PO 4 was determined 50 K. The temperature dependence of the magnetization curves showed magnetic phase transition from paramagnetic to antiferromagnetic at T N by SQUID measurement. Mössbauer spectra of LiFe 0.9 Mn 0.1 PO 4 showed 2 absorption lines at temperatures above T N and showed asymmetric 8 absorption lines at temperatures below T N . These spectra occurred due to the magnetic dipole and electric quardrupole interaction caused by strong crystalline field at asymmetric FeO 6 octahedral sites.