Pressure-induced amorphization of La1/3NbO3

La1/3NbO3, an A-site cation deficient double perovskite, has been studied under pressure by synchrotron X-ray powder diffraction and Raman spectroscopy. In contrast to other highly distorted perovskites, transforming to post-perovskite on compression, La1/3NbO3 undergoes irreversible pressure induced amorphization at ~14.5GPa. Over a wide range of pressure before that transition it presents an almost linear volume decrease versus pressure, accompanied by convergence form orthorhombic to a cubic unit cell. The Raman spectroscopy also shows an amorphization at the same pressure. However, where upon full decompression the X-ray diffraction pattern remains amorphous, new Raman peaks become active. ► La1/3NbO3 has been studied under pressure by synchrotron XRD and Raman spectroscopy. ► La1/3NbO3 undergoes irreversible pressure induced amorphization at ~14.5GPa. ► Upon full decompression the XRD pattern remains amorphous. ► However, part of the Raman spectrum reappears, and new Raman peaks become active.