MAGNETIC AND MAGNETO-OPTIC EFFECTS IN BARIUM FERRITE FILMS GROWN BY PULSED LASER DEPOSITION

Barium ferrite films have been grown by pulsed laser deposition on sapphire single crystalline substrates. With oxygen and at high temperatures (more than 700 °C), the films exhibit high orientation following the (001) texture. The anisotropy is always perpendicular, with the possibility of in plane component of the magnetisation with annealing at very high temperature (900 °C). The in plane component was attributed to the interdiffused layer which increases with the temperature and deteriorates the coercivity squareness. The magneto-optic measurements show two large peaks in the UV at 270 nm and 390 nm with +0.28 and -0.15 degree as Kerr rotation respectively. The two peaks correspond to the charge transfer transitions of the complex Fe+3-O-2 in which the Fe+3 can be either in tetrahedral or octahedral site. The difference in the peak signs was attrihuted to the antiferromagnetic exchange coupling between the tetrahedral and octahedral sites