Space group and crystal structure of the Perovskite CaTiO{sub 3} from 296 to 1720K

Journal Article · Thu Sep 15 04:00:00 EDT 2005 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2005.06.027· OSTI ID:20729096

Ali, Roushown ^[1]; Yashima, Masatomo ^[1]

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1. Department of Materials Science and Engineering, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8502 (Japan)

The structural phase transitions of the calcium titanate perovskite CaTiO{sub 3} were investigated by the Rietveld analysis of high-temperature neutron and X-ray powder diffraction data in the temperature range of 296-1720K. The present work demonstrates that the compound exhibits two reversible phase transitions of orthorhombic Pbnm-tetragonal I4/mcm and of I4/mcm-cubic Pm3-bar m at 1498+/-25K and 1634+/-13K, respectively. No evidence of Cmcm phase is observed between the Pbnm and I4/mcm structures. The lattice parameters discontinuously change at the Pbnm-I4/mcm transition point, while a continuous change is observed for the I4/mcm-Pm3-bar m transformation. These results indicate that the Pbnm-I4/mcm transition is of first order and that the I4/mcm-Pm3-bar m transformation is of either second or higher order.

• OSTI ID: 20729096
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 9 Vol. 178; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CALCIUM COMPOUNDS
CUBIC LATTICES
LATTICE PARAMETERS
NEUTRON DIFFRACTION
ORTHORHOMBIC LATTICES
PEROVSKITE
PHASE TRANSFORMATIONS
SPACE GROUPS
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
TETRAGONAL LATTICES
TITANATES
X-RAY DIFFRACTION