Journal of Magnetics 13(2), 61-64 (2008) ⓒ 2008 Journal of Magnetics Electrical Properties of SrRuO3 Thin Films with Varying c-axis Lattice Constant

We studied the effect of the variation of the lattice constant on the electrical properties of SrRuO3 thin films. In order to obtain films with different volumes, we varied the substrate temperature and oxygen pressure during the growth of the films on SrTiO3 (001) substrates. The films were grown using a pulsed laser deposition method. The X-ray diffraction patterns of the grown films at low temperature and low oxygen pressure indi-cated the elongation of the c-axis lattice constant compared to that of the films grown at a higher temperature and higher oxygen pressure. The in-plane strain states are maintained for all of the films, implying the expan-sion of the unit-cell volume by the oxygen vacancies. The variation of the electrical resistance reflects the tem-perature dependence of the resistivity of the metal, with a ferromagnetic transition temperature inferred form the cusp of the curve being observed in the range from 110 K to 150 K. As the c-axis lattice constant decreases, the transition temperature linearly increases