Enhancing the charge ordering temperature in thin films of Pr 0.5Ca 0.5MnO 3 by strain

Abstract

We report the effects of biaxial strain on the charge ordering temperature Tco of the mixed-valent manganite perovskite oxide Pr0.5 Ca0.5 Mn O3. Thin films were grown on SrTi O3, which has a 1.3% larger in-plane lattice parameter. Other substrates were used for comparison. Transport measurements combined with data from electron microscopy show that Tco is considerably enhanced. At thicknesses of the order of 10 nm, where the films are fully strained, Tco is above 320 K, more than 70 K above the bulk value of 250 K, while around 50 nm, where relaxation has set in, the enhancement is around 40 K. The bulk value is only reached at a thickness of about 150 nm. © 2006 American Institute of Physics.