Size effects on negative thermal expansion in cubic ScF{sub 3}

Journal Article · Mon Jul 11 04:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4959083· OSTI ID:22590572

Yang, C.; Guo, X. G.; Zhang, K. ^[1]; Lin, J. C.; Wang, M.; Wu, Y.; Lin, S.; Xu, W.; Song, W. H. ^[1]; Huang, P. C. ^[2]

---

1. Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)
2. University of Science and Technology of China, Hefei 230026 (China)

Scandium trifluoride (ScF{sub 3}), adopting a cubic ReO{sub 3}-type structure at ambient pressure, undergoes a pronounced negative thermal expansion (NTE) over a wide range of temperatures (10 K–1100 K). Here, we report the size effects on the NTE properties of ScF{sub 3}. The magnitude of NTE is reduced with diminishing the crystal size. As revealed by the specific heat measurement, the low-energy phonon vibrations which account for the NTE behavior are stiffened as the crystal size decreases. With decreasing the crystal size, the peaks in high-energy X-ray pair distribution function (PDF) become broad, which cannot be illuminated by local symmetry breaking. Instead, the broadened PDF peaks are strongly indicative of enhanced atomic displacements which are suggested to be responsible for the stiffening of NTE-related lattice vibrations. The present study suggests that the NTE properties of ReO{sub 3}-type and other open-framework materials can be effectively adjusted by controlling the crystal size.

• OSTI ID: 22590572
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 2 Vol. 109; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMIC DISPLACEMENTS
CRYSTALS
DISTRIBUTION FUNCTIONS
LATTICE VIBRATIONS
PHONONS
RHENIUM OXIDES
SCANDIUM
SPECIFIC HEAT
THERMAL EXPANSION