Pr_0.5Ca_0.5MnO₃ thin films deposited on LiNbO₃ substrates

¹ Centro de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
² IFIMUP/IN-Instituto de Nanociência e Nanotecnologia, R. Campo Alegre 4169-007 Porto, Portugal
³ Universidade do Porto-DFA Faculdade de Ciências, R. Campo Alegre, 4169-007 Porto, Portugal

Abstract

Thin films of Pr_0.5Ca_0.5MnO₃ have been deposited on z-cut LiNbO₃ by pulsed laser ablation. The Xray diffraction measurements showed that the films have grown highly oriented on LiNbO₃, with a pseudocubic (111) preferred growth direction. The thicknesses of the films, measured by low angle X-ray reflectivity, are between 13 and 140 nm. Their electrical resistivity present a semiconducting-like behaviour with an anomaly around 240 K, that corresponds to the charge ordering transition. The temperature of the transition (T_CO) was estimated from ln ρ vs. (1/T) plots. The charge ordering temperature was found to be dependent on the strain induced by the lattice mismatch on the films.