Enhanced negative thermal expansion in Lu{sub 2}W{sub 3}O{sub 12}

Journal Article · Thu Oct 01 04:00:00 EDT 1998 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1998.7967· OSTI ID:305398

Forster, P M; Yokochi, A; Sleight, A W ^[1]

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1. Oregon State Univ., Corvallis, OR (United States)

Negative thermal expansion in the Sc{sub 2}W{sub 3}O{sub 12} family has been pushed to much more pronounced values by substituting a large cation for Sc. X-ray diffraction measurements from 127 to 627 C give a linear thermal expansion coefficient of {minus}6.8 {times} 10{sup {minus}6}/{degree}C for Lu{sub 2}W{sub 3}O{sub 12} compared to {minus}2.2 {times} 10{sup {minus}6}/{degree}C for Sc{sub 2}W{sub 3}O{sub 12}. Negative thermal expansion in this family is dependent on the rocking motions of polyhedra. However, polyhedra in this structure cannot rock without changed their shape. Larger cations expand the octahedra, reducing the oxygen-oxygen repulsions within the polyhedra. This facilitates the polyhedra shape changes necessary for the rocking motions required for negative thermal expansion.

• Sponsoring Organization: National Science Foundation, Washington, DC (United States)
• OSTI ID: 305398
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 140; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
EXPERIMENTAL DATA
LUTETIUM OXIDES
TEMPERATURE RANGE 0400-1000 K
THERMAL EXPANSION
TUNGSTEN OXIDES
X-RAY DIFFRACTION