Pulsed laser deposition thin films of Pr0.7Sr0.3MnO3: The role of growth temperature

Pr0.7Sr0.8MnO3 thin films were deposited at different temperatures on [100] -LaAlO3 substrates by the pulsed laser deposition (PLD) technique. X-ray di ffraction, electron diffraction, and high-resolution electron microscopy (H REM) show that the deposition temperature influences dramatically the orien tation of the films and their microstructure, within a very short range. Th e films grown at low temperature are [101]-oriented and exhibit a columnar growth with well-connected grains. One observes the coexistence of [010]- a nd [101]-oriented domains poorly connected platelet-like crystals, for film s deposited at high temperature. The HREM observation of a cross section of the low-temperature thin film reveals the presence of an interfacial strai ned layer close to the substrate, allowing a growth mechanism to be propose d. The magnetic measurements show that the Curie temperature is independent of the growth temperature. In contrast, the magnetotransport properties ar e strongly influenced, due to the different nature of the microstructure an d especially to the role of the grain boundaries that may exhibit a depress ed T-c.