The Lattice Structure, Raman Spectra, Electronic Structure, and Magnetic Properties of RCrO3 (R = Ho and Sm) Films: the Effect of Thickness

The crystal structure, electronic structure, and magnetic properties of HoCrO3 and SmCrO3 films with thickness grown on Si (100) substrates using a sol-gel method have been investigated. The lattice parameters and orthorhombic distortion of polycrystalline films are affected by the thickness. X-ray photoelectron spectroscopy shows that Cr ions in all samples are trivalent. When HoCrO3 films get thin, the hybridization of Ho 4 f with O 2 p orbital is strengthened, while the hybridization of O 2 p and Cr 3 d is more prominent in SmCrO3. The negative magnetization occurs both for HoCrO3 and SmCrO3 films, and it is enhanced with increase of the HoCrO3 film thickness. Moreover, exchange bias effect is observed in HoCrO3 film. With respect to HoCrO3 film, the magnetic effect of SmCrO3 is more sensitive to the film thickness.