Electron spin resonance and magnetization in La0.67Ca0.33MnO3 thin films

We report electron spin resonance (ESR) and magnetization measurements in La0.67Ca0.33MnO3 thin films deposited on LaAlO3 single-crystal substrates by DC sputtering technique. Angular and temperature dependence of resonance field (H-Res) and ESR line-width (Delta H-PP) were measured in the ferromagnetic and paramagnetic regime. Above T-C, H-Res is not shifted, while below T-C, H-Res for H-perpendicular to and H-parallel to diverge, due to the presence of magnetic anisotropy and demagnetizing fields. Besides, when T is approaching T-C from above, the Delta H-PP goes to a minimum (approximate to 200 G) and Delta H-PP increases below T-C. Temperature dependence of magnetization in the films was obtained by using the relationship of H-Res. These values were compared with SQUID measurements. Finally, we estimated the gyromagnetic factor in 1.996(6). (c) 2006 Elsevier B.V. All rights reserved.