Electron spin resonance and magnetization in La 0.67Ca 0.33MnO 3 thin films

Abstract

We report electron spin resonance (ESR) and magnetization measurements in La 0.67Ca 0.33MnO 3 thin films deposited on LaAlO 3 single-crystal substrates by DC sputtering technique. Angular and temperature dependence of resonance field ( H Res) and ESR line-width (Δ 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 ⊥ and H ∥ diverge, due to the presence of magnetic anisotropy and demagnetizing fields. Besides, when T is approaching T C from above, the Δ H PP goes to a minimum (≈200 G) and Δ 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).