BiCu0.5Mn0.5O3: a new RT magnetic perovskite from High Pressure/High Temperature synthesis

Double perovskites (A2BB’O6), with their tolerance to chemical substitutions and structural distortions, represent a versatile playground for inducing multiple functionalities in a single phase, like multiferroicity, spin-polarized carriers, and photovoltaic effects. However, their potential application is usually limited by the low onset temperature of the magnetic state. For the first time to our knowledge, we have synthesized under High Pressure/High-Temperature conditions a new perovskite, BiCu0.5Mn0.5O3 (BCMO), with a ferromagnetic-like transition and spontaneous magnetization above RT. From TEM and PXRD we have identified the crystal structure and symmetry, with a Lead Zirconate-type distortion and the Bi shifted along the 111 pseudocubic direction but the exact position of the O and the distribution of Mn/Cu on the B site need to be confirmed by neutron diffraction. Moreover, an AFM order at lower T has been detected, coming from a deep modification of the electric character from a thermal-activated transport to a hopping mechanism, with a partial localization of the electrons on Mn4+. These results depict an interesting interplay between electronic properties and the complex magnetic behaviour of BCMO. The small sample size due to the synthesis method, combined with the need for high-resolution data to characterize the nuclear structure and access to long d-spacing for the magnetic structure solution, make WISH the perfect instrument for this proposal.