Epitaxial growth and transport property of La0.9Sr0.1MnO3 thin films deposited on MgO, LaAlO3 and SrTiO3 substrates

Abstract

La0.9Sr0.1MnO3 (LSMO) thin films were grown on (100)-oriented MgO, LaAlO3 and SrTiO3 substrates by pulsed laser deposition, so as to investigate the effect of substrate-induced lattice mismatch on epitaxial growth, electrical resistivity and transport behavior of the films. The X-ray diffraction patterns and pole figures indicated that the LSMO thin films were epitaxially grown on the three kinds of substrate, and the orientation relationship was found to be LSMO (100) [010]//substrate (100) [010]. The measurement of electrical resistivity showed that the LSMO thin films were characteristic of semiconductor, and the transport mechanism was dominated by the small polaron hopping (SPH) model. Compared with MgO and LaAlO3 substrates, the LSMO thin films grown on SrTiO3 substrate exhibited lower resistivity and smaller conductivity hopping energy, due to the less lattice mismatch at film/substrate interface which tended to reduce the Jahn-Teller distortion and thus the localization of charge carriers was decreased.