CoMn₂O₄ 스피넬 박막의 합성과 후열처리가 박막의 물리적 특성에 미치는 영향

We grew spinel structured CoMn₂O₄ thin films and have studied post-growth annealing effects on their physical properties. After post-growth annealing at 700℃ that is lower than the growth temperature (720℃), crystal structure became cleared accompanying a change of surface structure. In the temperature dependences of magnetization, phase transitions were observed at ~100 K for both before and after post-growth treated samples which were not observed for the bulk. For both samples, ferromagnetic behaviors were observed above 100 K while it turned to ferrimagnetism at low temperature below 100 K. In particular, the ferrimagnetic behavior became strong after the post-growth treatment. These results indicate that the post-growth annealing process plays an important role in determining the physical properties of spinel CoMn₂O₄ thin film.