Electric Transport And Magnetic Properties Of Labaco2o6_ Delta Single-Crystal Films Grown On Srtio3 Substrates

Deposition atmosphere was found to have significant impacts on the growth of single-crystal LaBaCo2O6_delta (LBCO) films. In 2 x 10_4 Pa, the LBCO film grew basically along the c-axis of LaBaCo2O5.5 and high-quality single-crystal LBCO film was obtained after O2 annealing. In 2 Pa of O2, the dominant domains in the LBCO film became a- and/or b-axis oriented and a phase separation appeared in the O-annealed film. The O-annealed LBCO films exhibited an obvious paramagnetic to ferromagnetic transition at -200 K and -1.3 mu B/Co of saturated magnetic moment was obtained at 10 K. Ferromagnetic and spin-glass-like states may coexist in the LBCO films, making a deviation of the zero-field-cooled from the field-cooled magnetization at temperatures below an irreversible temperature. The LBCO films exhibited the magnetic properties close to that of nanoscale-ordered LaBaCo2O6, but the electric transport behaviors are close to that of ordered LaBaCo2O6.