Phase separation in La5/8Sr3/8MnO3 (30%)+LuMnO3 (70%) bulk sample studied by scanning microwave microscopy

Abstract

Using a scanning microwave microscope (SMM), we have investigated the phase separation in a 30% La5/8Sr3/8MnO3 (LSMO)+70% LuMnO3 (LMO) polycrystalline pressed powder sample, in which the LSMO phase is a perovskite ferromagnetic metal while the LMO phase is a hexagonal ferroelectric insulator. When the electrical properties of the sample were imaged using our SMM, the sample showed a significant contrast between the metallic LSMO and the insulating LMO grains, indicating a clear phase separation between the two phases. The metallic phase identified by the SMM clearly showed a ferromagnetic signal when investigated by a magnetic force microscope (MFM), providing solid evidence that the metallic phase is indeed the ferromagnetic LSMO. In addition, we have noticed a slight difference between the images generated by SMM and MFM, and we believe that this is due to the different depth scales probed by the two microscopy techniques. (C) 2005 American Institute of Physics.