Pressure induced phase transition in periodic microtwinned thin film of La0.88Sr0.1MnO3

We have studied the resistivity of a hole-doped 95nm thin film of La0.88Sr0.1MnO3 sample as a function of pressure up to 2.0GPa. For pressures below 0.81GPa, the sample showed that the resistivity decreased at all temperatures and the metal insulator transition temperature TMI increased to higher temperatures similar to the pressure results observed previously in bulk samples and thin films of manganites. However, for pressures above 0.81GPa, we observed a rapid increase in resistivity and a rapid decrease of TMI as a function of pressure. The rate of change of TMI with pressure is −133.5K∕GPa which is an order of magnitude larger than that of bulk samples and thin films of manganite with an opposite sign. We interpreted our results as a consequence of a phase change in the film by pressure from having strain induced periodic microtwinned regions below 0.81GPa to a strained free region and formation of coherent twins above this pressure in 95nm thin film of La0.88Sr0.1MnO3.