Pulsed Laser Deposition Thin Films of Pr0.7Sr0.3MnO3: The Role of Growth Temperature

Pr 0.7 Sr 0.3 MnO 3 thin films were deposited at different temperatures on [100]-LaAlO 3 substrates by the pulsed laser deposition (PLD) technique. X-ray diffraction, electron diffraction, and high-resolution electron microscopy (HREM) show that the deposition temperature influences dramatically the orientation of the films and their microstructure, within a very short range. The films grown at low temperature are [101]-oriented and exhibit a columnar growth with well-connected grains. One observes the coexistence of [010]- and [101]-oriented domains poorly connected platelet-like crystals, for films deposited at high temperature. The HREM observation of a cross section of the low-temperature thin film reveals the presence of an interfacial strained layer close to the substrate, allowing a growth mechanism to be proposed. The magnetic measurements show that the Curie temperature is independent of the growth temperature. In contrast, the magnetotransport properties are strongly influenced, due to the different nature of the microstructure and especially to the role of the grain boundaries that may exhibit a depressed T c .