In situ oxygen control and high thermal stability of epitaxial (La 1− xNd x) 0.7Sr 0.3MnO 3 films fabricated by pulsed laser deposition

Abstract

In this work, epitaxial (La 1− x Nd x ) 0.7Sr 0.3MnO 3 ( x=0, 0.5 and 1) films have been grown on LaAlO 3(001) substrates at an oxygen ambient of 400–10 mtorr by pulsed laser deposition. As a result, the oxygen contents and hence the metal–semiconductor transition temperature and the overall resistivity of the films were tuned systematically. The relationship between the transition temperature and the environmental oxygen pressure for film growth was compared with that for fabricating bulk manganate perovskites. It is found that the oxygen content of the epitaxial films is stable against post-deposition heat treatments. The electrical transport behavior of the as-deposited films remains unchanged even after in situ annealing at the deposition temperature and in oxygen pressure ranging from 2×10 −6 to 760 torr. Our results suggest that the manganate films are very desirable for fabrication of the epitaxial all-perovskite-type oxide heterostructures.