Magnetic and magneto-optic properties of orthoferrite thin films grown by pulsed-laser deposition

Thin magnetic layers have been prepared by pulsed-laser deposition from tar gets of the orthoferrites: DyFeO3, GdFeO3, SmFeO3, and YFeO3. All layers we re deposited onto quartz substrates at a temperature of 450 degrees C under high-vacuum conditions, i.e., in the absence of additional oxygen. The as- grown films show evidence of the following phases: RFeO3, R3Fe5O12, Fe3O4, and R2O3, where R=Dy, Gd, Sm, and Y. The magnetic properties of these films have been investigated using superconducting quantum interference device m agnetometry and magneto-optic (Faraday rotation) measurements taken before and after annealing. These studies reveal that the orthoferrite phase is al most completely (> 90%) recovered after an annealing treatment at 860 degre es C for 1 h. We also report on the temperature dependence of the Faraday r otation for these orthoferrites in the temperature range 25-250 degrees C. (C) 1999 American Institute of Physics. [S0021-8979(99)02222-7].