Stabilization of 6H-Hexagonal SrMnO3 Polymorph by Al2O3 insertion |
| |
Authors: | Muhammad Sheeraz Mamoon Ur Rashid Asad Ali Fazli Akram Ho Jeong Lee Jin San Choi Jong-Seong Bae Yong Soo Kim Young-Han Shin Chang Won Ahn Tae Heon Kim |
| |
Affiliation: | 1. Department of Physics and Energy Harvest-Storage Research Center (EHSRC), University of Ulsan, Ulsan, 44610, Republic of Korea;2. Department of Physics, University of Ulsan, Ulsan, 44610, Republic of Korea;3. Busan Center, Korea Basic Science Institute (KBSI), Busan, 46742, Republic of Korea |
| |
Abstract: | We demonstrate the structural evolution of polymorphic phases in Al2O3-inserted SrMnO3 ceramics synthesized by solid state reaction. While the 4H-hexagonal phase is predominant in pure SrMnO3 ceramics, a small amount of 6H-hexagonal polymorph is identified in addition to the primary 4H-hexagonal SrMnO3 and the secondary hexagonal SrAl2O4 phases in the as-sintered ceramics, evidenced by x-ray diffraction and subsequent Rietveld refinement analyses. The existence of the 6H-hexagonal SrMnO3 phase is corroborated using Raman spectroscopy. The chemical compositions and electronic structures of the Al2O3-inserted SrMnO3 compounds are also examined using energy dispersive spectroscopy and x-ray photoelectron spectroscopy, respectively. The first-principles calculations reveal that there is no clear difference between the total energies of 4H- and 6H-hexagonal polymorphs regardless of the presence/absence of Sr and oxygen vacancies. Possible origins are discussed with the estimation of actual strain based on the refined lattice parameter of 6H SrMnO3. |
| |
Keywords: | Ceramics Oxide Structural phase transition X-ray diffraction |
本文献已被 ScienceDirect 等数据库收录! |
|