Suppression of the metal-insulator transition temperature in thin La0.7Sr0.3MnO3 films

In this paper, we illustrate an approach to discriminate between epitaxial strain and other factors responsible for the decrease of the metal-insulator transition temperature (T-P) in thin La0.7Sr0.3MnO3 films grown by pulsed laser deposition. Using this approach, we have estimated the effect of the biaxial strain on T-P. Ultrathin films, independent of epitaxial strain, do not show any metal-insulator transition over the full temperature range. This finding confirms the existence of an interface dead layer. The strain-independent decrease in T-P, relative to its bulk value, observed for a much wider thickness range (up to about 1000 A) can most likely be attributed to oxygen deficiency. (C) 2004 American Institute of Physics.