Magnetoresistant La sub(1-x)Sr sub(x)MnO sub(3) films by pulsed injection metal organic chemical vapor deposition: Effect of deposition conditions, substrate material and film thickness

• Published in: Thin solid films 2002-06, Vol.413 (1-2), p.32-40
• Main Authors: Plausinaitiene, V, Kubilius, V, Teiserskis, A, Saltyte, Z, Butkute, R, Senateur, J P, Abrutis, Adulfas
• Format: Article
• Language: English
• ISSN: 0040-6090

High quality epitaxial La sub(1-x)Sr sub(x)MnO sub(3) films were deposited by pulsed injection metal organic chemical vapor deposition, using as precursor materials metal-2,2,6,6-tetramethyl-3,5-heptandionates dissolved in monoglyme. The influence of various deposition conditions, substrate material and film thickness on film properties was investigated. The best films were deposited on LaAlO sub(3) substrates at 825 degree C: films exhibited a sharp semiconductor-metal transition and high magnetoresistance ([similar to]40%) at a close-to-room temperature and in a rather low field of 1.5 T. In-situ or ex-situ high-temperature annealing in oxygen increased the temperature of semiconductor-metal transition, but decreased the magnetoresistance and the temperature coefficient of resistance. Biaxial strain imposed by the lattices' mismatch was clearly observed in thinner La sub(1-x)Sr sub(x)MnO sub(3) films on perovskite substrates. Tensile strain was present in the films on SrTiO sub(3) and compressive strain in the films on LaAlO sub(3) (and less clearly on NdGaO sub(3)). Both tensile and compressive strains decreased the temperature of electric transition and the values of magnetoresistance. The strain was completely relaxed in the films more than [similar to]100 nm thick. copyright 2002 Elsevier Science B.V. All rights reserved.