Magneto-transport properties of [La.sub.0.7][Ca.sub.0.3-x][Sr.sub.x]Mn[O.sub.3] thin films deposited by pulsed electron deposition

We report the magneto-transport properties of [La.sub.0.7][Ca.sub.0.3-x][Sr.sub.x]Mn[O.sub.3] (x = 0, 0.075, 0.1, 0.125, 0.15, 0.3) thin films on (100) LaAl[O.sub.3] substrates prepared by pulsed electron-beam deposition (PED). With increasing x from 0 to 0.3, both Curie temperature ([T.sub.C]) and metal-insulator transition temperature ([T.sub.MI]) of the films were increased from 206 and 212 K to 339 and 366 K, respectively. Except x = 0.125 film, with increasing x, all other LCSMO films showed a tendency of gradual decrease in the maximum MR ratios ([MR.sub.MAX]) at increased maximum MR temperature ([T.sub.MAX],) values. The film of x = 0.125 exhibited extraordinary high [MR.sub.MAX] value of 16% at 306 K. After post-annealing in a pure oxygen atmosphere at 900[degrees]C, this film showed more enhanced [MR.sub.MAX] of 18% at 325 K. Index Terms--Colossal magnetoresistance (CMR), perovskite manganites films, pulsed electron-beam deposition (PED).