Pressure-induced structural phase transition in multiferroic KBiFe2O5

Multiferroics materials have been intensively investigated for applications into photovoltaic cells. KBiFe2O5 (KBFO) emerged as a strong candidate for such applications since it exhibits low bandgap energy. It is usually orthorhombic at room temperature and pressure, however, phase diagrams investigations determined that it transforms into a monoclinic structure at high temperatures and pressures. This monoclinic structure has more interesting multiferroic and electronic properties for photovoltaic applications. In this paper, we obtained such monoclinic phase at room temperature and pressure and investigated its stability under pressure changes. We showed KBFO undergoes a new reversible first-order structural phase transition into an orthorhombic structure at high pressures as determined by synchrotron X-ray diffraction and Raman spectroscopy measurements. (C) 2019 Elsevier B.V. All rights reserved.