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

• Speaker: Prof. Oh, Yoon Seok (UNIST)
• Date: Wednesday December 12, 2018 05:00pm
• Place: Jungho Seminar Room

Named after Russian mineralogist L. Perovski, Perovskite is material which has the chemical formula ABX₃ (where 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-T_c 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. Recently, we successfully grow stoichiometric cubic BaZrO₃ single crystal, whose energy band gap is 5.0 eV, with size of 5 mm × 5 mm × 5 mm. Using X-ray diffraction, atomic force microscope, ultraviolet-visible-near-infrared transmission spectra, transmission electron microscope, comprehensive structure and electronic properties have been studied.