Biaxial strain and orbital order in la_2/3Ca _1/3MnO₃ thin films

Biaxially strain is an important parameter in the complex phase diagram of the doped manganites that can lead to a different groundstate compared to bulk single crystals at the same doping level. For coherently strained La _2/3Ca_1/3MnO₃ thin films on SrTiO₃ substrates, we report an unusual direction dependence of the electrical transport properties. For transport perpendicular to the substrate induced strained plane, an insulating behavior associated with non-linear current-voltage characteristics is observed. We propose an A-type antiferromagnetic groundstate for the biaxially strained films as is consistent with the observed strongly reduced saturation magnetization.