Phase transition and possible metallization in CeVO{sub 4} under pressure

Journal Article · Mon Jul 15 00:00:00 EDT 2013 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2013.04.036· OSTI ID:22309047

Shanavas, K. V. ^[1]; Wani, B. N. ^[2]; Sharma, Surinder M. ^[1]

---

1. High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India)
2. Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India)

Phase stability of CeVO{sub 4} under pressure has been investigated using synchrotron based angle dispersive x-ray diffraction (ADXRD), electrical resistance and first principles calculations. The results indicate that the ambient zircon structure of the compound transforms to a low symmetry monoclinic monazite phase beyond 3.8 GPa with nearly 8.6% volume discontinuity. Beyond 11 GPa, the pattern could be fitted to a similar monazite structure which is about 12.7% denser and has a much larger monoclinic beta angle. On pressure release the first monoclinic phase is recovered. The electrical resistance data show a large drop in resistance with pressure indicating substantial narrowing down of the band gap. Electronic structure calculations support these observations and suggest possible pressure induced metallization in this material. - Pressure induced structural phase transition in CeVO{sub 4} as observed by x- ray diffraction (pressure vs. volume) and possible metallization in CeVO{sub 4} through electrical resistance and first principles electronic structure calculations. - Highlights: • Structural and electrical behavior of CeVO{sub 4} under pressure studied using x-ray diffraction and electrical resistance measurements and first principles calculations. • Two successive structural transitions confirmed by experiment and theory: zircon–monazite I–monazite II. • Band gap collapse and possible metallization is indicated by electrical resistance measurements and electronic structure calculations under pressure. • Novel observation of lower bulk modulus in the high pressure phase (both by experiment and calculations) explained through structural analysis.

• OSTI ID: 22309047
• Journal Information: Journal of Solid State Chemistry, Vol. 203; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ELECTRIC CONDUCTIVITY
ELECTRONIC STRUCTURE
MONAZITES
MONOCLINIC LATTICES
PHASE STABILITY
PHASE TRANSFORMATIONS
PRESSURE RELEASE
SYNCHROTRONS
X-RAY DIFFRACTION
ZIRCON