Large Lattice Constant and Large Band Gap Cubic Perovskite: BaZrO3 Single Crystal

Abstract

Abstract:

Named after Russian mineralogist L. Perovski, Perovskite is material which has the chemical formula ABX3 (A and B are cations, and X is an anion) and a crystal structure with the anion X in the face centers. The Perovskite compounds exhibit a variety of exotic physical phenomena, such as high-Tc superconductivity as well as quantum criticality, heavy fermion, multiferroics, morphotropic phase boundary. In terms of new functional material design, the Perovskite has high tunability. It’s possible that selective chemical substitution of atomic sites induces various orthorhombic distortions as well as cubic. In addition, it can also form layered structure, so called Ruddlesden-Popper structure, composed of one or multiple ABX3 two-dimensional perovskite slabs and AX rock salt interleave layers. Recently, in the hybrid inorganic-organic framework with the Perovskite architecture, highly efficient solar cell application was demonstrated. Because of its variety and the intriguing physics, there has been lots of attention to Perovskite compounds during the last 30 years. Among plenty of the Perovskite compounds with the fascinating physical property, insulating Perovskite oxides, such as SrTiO3, LaAlO3, DyScO3, are utilized as substrate to grow epitaxial films. The compressive and tensile strains due to lattice mismatch between the substrate and the film coin multifunctional electronics and magnetism of the epitaxial grown film. In this research, stoichiometric cubic BaZrO3 single crystal, whose lattice constant is 7.5 % larger than that of SrTiO3, is successfully grown with size of 5 mm × 5 mm × 5 mm. Using X-ray diffraction, atomic force microscope, ultraviolet-visible-near-infrared transmission spectra, and transmission electron microscope, comprehensive structure and electronic properties have been studied.