Effect of substrate temperature on magnetic properties of MnFe2O4 thin films

MnFe2O4 thin films were pulsed laser deposited on to quartz substrate from room temperature (RT) to 650 degrees C in a pure argon environment. Temperature dependence of spontaneous magnetization (4 pi M-S) was measured on these films from 10 K to 350 K using a vibrating sample magnetometer. Ferromagnetic resonance (FMR) study was also carried out at 300 K. The exchange stiffness constant (D) values were obtained by fitting the 4 pi M-S data to the Bloch's equation. The D values of the films thus found decreases while the 4 pi M-S value increases, though non-monotonically, with the increase in T-S and tend to reach bulk values at T-S = 650 degrees C. The variation in D and 4 pi M-S values of the films are explained based on the degree of inversion and oxidation state of cations in thin films. (C) 2017 Author(s)