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Author Lahoz, F. ♦ Villacampa, B. ♦ Alcala, R. ♦ Marquina, C. ♦ Ibarra, M. R.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ RUBIDIUM FLUORIDES ♦ CRYSTAL-PHASE TRANSFORMATIONS ♦ CESIUM FLUORIDES ♦ CALCIUM FLUORIDES ♦ MIXING HEAT ♦ CRYSTAL STRUCTURE ♦ SOLID SOLUTIONS ♦ CRYSTAL LATTICES ♦ THERMAL EXPANSION ♦ PARAMAGNETISM ♦ CUBIC LATTICES ♦ TETRAGONAL LATTICES ♦ LATTICE PARAMETERS ♦ ELECTRON SPIN RESONANCE
Abstract The influence of crystal mixing on the structural phase transitions in Rb{sub 1{minus}x}Cs{sub x}CaF{sub 3} (0{lt}x{lt}1) fluoroperovskite crystals has been studied by thermal expansion and EPR measurements of Ni{sup 2+} and Ni{sup 3+} paramagnetic probes. A cubic-to-tetragonal phase transition has been detected in crystals with x=0, 0.1, 0.21, 0.27, and 0.35. The critical temperature and the tetragonal distortion decrease as x increases. No transition was observed for x{ge}0.44. This transition shows a weak first-order component in the x=0 and 0.1 samples, which is progressively smeared out for x{gt}0.1, indicating a spatial distribution of the critical temperature in those crystals with high ionic substitution rate. In RbCaF{sub 3}, another structural phase transition was observed at 20 K with a thermal hysteresis between 20 and 40 K. This transition has not been found in any of the mixed crystals.
ISSN 01631829
Educational Use Research
Learning Resource Type Article
Publisher Date 1997-04-01
Publisher Place United States
Journal Physical Review, B: Condensed Matter
Volume Number 55
Issue Number 13


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