Preference orientation and magnetic properties of CoxFe3-xO4 nanocrystalline thin films on quartz substrate

Nanocrystalline spinel ferrite thin films of CoxFe3-xO4 (x = 0.31, 0.5, 0.8, and 1.0) have been prepared by RF sputtering on quartz substrate without a buffer layer at room temperature and annealed at the temperature range from 200 to 600 degrees C in air. The as-sputtered films exhibit the preferred orientation and the high magnetization and coercivity. After annealing, the preferred orientations become poor, but the magnetization and coercivity increase. The sample with a magnetization of 455 emu/cm(3), a coercivity of 2.8 kOe, a remanence ratio of 0.72, and a maximum energy product of 2.4 MGOe has been obtained. The influence of Co ions and annealing temperature on the magnetic properties has been discussed. (c) 2005 Elsevier B.V. All rights reserved.