Magnetic Properties of (111)-Oriented Co 0.8 − x Mn x Fe 2.2 O 4 ( x = 0 − 0.3 ) $\text {Co}_{\mathrm {0.8}_{-x}} \text {Mn}_{x} \text {Fe}_{\mathrm {2.2}}\text {O}_{\mathrm {4}}( {x}=0-0.3)$ Thin Films Grown by Pulsed Laser Deposition

$\text {Co}_{\mathrm {0.8}_{-{x}}}\text {Mn}_{x} \text {Fe}_{\mathrm {2.2}}\text {O}_{\mathrm {4}} (\textit {x}~=~0-0.3)$ thin films were grown on Pt(111)/Si substrate by pulsed laser deposition technique at an oxygen pressure of 10 mTorr and substrate temperature of 600 °C. The films have a perfect (111) orientation and compacted nano-sized grain-feature surface morphology (50–80 nm). Mn substitution leads to an increase in lattice constant indicating the presence of Mn in Mn2+ state rather than Mn3+. The observed increase in magnetization with increasing Mn content could be attributed to the higher magnetic moment of Mn2+ than that of Co2+. In addition, the coercivity of the films decreased with increasing Mn content.