High field electron spin resonance measurements on La0.67Ca0.33MnO3 thin films

La0.67Ca0.33MnO3 thin films of different thicknesses have been studied by h igh frequency-high magnetic field ESR. The thinner one (150 nm) presents on e single ESR line revealing a good homogeneity. We have determined its gyro magnetic tensor, which presents a slight anisotropy as regards the film pla ne: g(parallel to) = 1.97 and g(perpendicular to) = 1.99. These values are in agreement with spin-orbit coupling. The magnetic anisotropy is uniaxial, within the film plane. The anisotropy field at low temperature is 0.07 T, a magnitude comparable to that observed in bulk compounds. (C) 2000 Elsevie r Science Ltd. All rights reserved.