Growth of single-phase c-axis aligned La1.2Ca1.8Mn2O7 films on SrTiO3 (001)

We report the growth of single phase, c-axis aligned thin films of La_1.2Ca_1.8Mn₂O₇ on SrTiO₃ (001) substrates using a controlled pulsed laser deposition method. In this method, constraint of epitaxy is utilized to stabilize the Ruddlesdon-Popper (RP) phase of La_1.2Ca_1.8Mn₂O₇. Oxygen ambient pressure and the rate of deposition play a very important role in influencing the epitaxial growth as well as maintaining phase purity of the material. The oxygen pressure inside the deposition chamber was very precisely controlled and varied during the layer-by-layer growth of the film. Films, prepared by our method, show excellent electrical and magnetic characteristics with a sharp metal-insulator transition at T_M-I=90 K, closely followed by a magnetic transition at T_C=91 K.