Structural phase transformations of BiCu0.4Mn0.6O3 magnetic perovskite under high pressure-high temperature conditions

We propose to investigate the structural phase transformation of BiCu0.4Mn0.6O3 (BCMO) under High Pressure-High temperature (HP-HT) conditions using in-situ Powder X-ray diffraction (PXRD) and X-ray Absorption Spectroscopy (XAS). BCMO is a newly room-temperature (RT) magnetic perovskite, obtained via HP-HT synthesis. Preliminary synchrotron experiments demonstrate that BCMO undergoes a phase transformation at 4-6 GPa and 600°C-700°C which upon quenching to ambient condition give rise to a new phase with enhanced ferromagnetism. The proposed PXRD and XAS experiments at ID15b and BM23 will be pivotal to solve the bulk and local atomic structures of these two new phases and to understand the role of the cation valence in their macroscopic properties.