First-Principles Study of Structural Trend of Bi$M$O3 and Ba$M$O3: Relationship between Tetragonal or Rhombohedral Structure and the Tolerance Factors

• Published in: Jpn J Appl Phys 2010-03, Vol.49 (3), p.031501-031501-6
• Main Author: Miura, Kaoru
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.49.031501

The relationship between a tetragonal or rhombohedral structure and the tolerance factors in Bi$M$O 3 and Ba$M$O 3 has been investigated using a first-principles calculation with optimized structures. Bi$M$O 3 and Ba$M$O 3 , which consist of $M$ ions with d 0 -state transition metals (TMs) or non-TMs, were optimized within frameworks of $P4mm$ (tetragonal) and $R3m$ (rhombohedral) structures, and their total energies ($E_{\text{tetra}}$ and $E_{\text{rhombo}}$, respectively) were compared. In Bi$M$O 3 , except for BiGaO 3 , the total energy difference $\Delta E$ ($\equiv E_{\text{rhombo}}-E_{\text{tetra}}$) as a function of the tolerance factor $t$ increases monotonically and smoothly, and the critical value from negative to positive in $\Delta E$ is about 1.00. In BiGaO 3 with d 10 -state Ga ions, the tetragonal structure is more stable despite $t