Investigation of the magnetic properties of Li0.8Na0.2FePO4 by using the Mossbauer spectroscopy

We have investigated Li0.8Na0.2FePO4, a cathode material for secondary battery applications, by using X-ray diffractometry (XRD), vibrating sample magnetometry (VSM) and Mossbauer spectroscopy. The crystal structure is found to be orthorhombic with lattice parameters of a (0) = 10.333 , b (0) = 6.011 and c (0) = 4.700 . From the temperature dependence of both the magnetization and the Mossbauer spectra, the N,el temperature is found to be T (N) = 51 K and the spin reorientation temperature to be T (S) = 20 K. The magnetic hyperfine field (H (hf) ), electric quadrupole splitting (Delta E (Q) ) and isomer shift (delta) at 4.2 K are found to be H (hf) = 130.50 kOe, Delta E (Q) = 2.63 mm/s and delta = 1.25 mm/s.