MnFe2O4 thin films were pulsed laser deposited on to quartz substrate from room temperature (RT) to 650 °C in a pure argon environment. Temperature dependence of spontaneous magnetization (4πMS) 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 4πMS data to the Bloch’s equation. The D values of the films thus found decreases while the 4πMS value increases, though non-monotonically, with the increase in TS and tend to reach bulk values at TS = 650 °C. The variation in D and 4πMS values of the films are explained based on the degree of inversion and oxidation state of cations in thin films.

Single phase nano-crystalline zinc ferrite thin films were deposited by RF-magnetron sputtering on quartz substrate at room temperature (RT) in pure Argon environment and annealed (in air) at different temperatures. Temperature dependence of magnetization was studied on these films using both VSM and by observing FMR (in X band). Value of exchange stiffness constant (D) was obtained by fitting Bloch’s law to the low temperature magnetization data. The value of D decreased monotonously with the annealing temperature (TA) of the samples. A film annealed at TA = 523 K, exhibited the highest magnetization value. The FMR line width of the films decreased with increase in measurement temperature. At RT (∼293 K), the lowest value of line width (ΔH) was 15 kA/m and 13 kA/m in parallel and perpendicular configuration respectively for the sample annealed at TA = 623 K.

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