Optimum oxygen content in La0.7Sr0.3MnO3 thin films

The technological conditions of oxygen content variation in epitaxial La0.7Sr0.3MnO3-{\delta} films and the peculiarities of change of their transport characteristics were investigated. The films were grown onto single crystal SrTiO3 substrates by an enhanced method of dc magnetron sputtering of a ceramic target. It was revealed, that the oxygen content of the film material with initially strong deviation from stoichiometric composition ({\delta}>0.06) changes easily in both directions at temperatures Tp >=870 K, and the result of the oxygen content variation can be well controlled via changes of conductivity minimum temperature ™. The particularities of indirect accurate control of the oxygen content in the film are described. The existence of oxygen-excessive composition of the film is in principal agreement with the known phase diagrams for a powder samples. It was revealed, the oxygen-excessive content of the film causes the increase of free charge carriers concentration and the decrease of the film conductivity in ferromagnetic state. It is shown, that the oxygen-deficient films can demonstrate the same peculiarity of magnetotransport properties as the films with a deviation from stoichiometric content in cation composition.