Discontinuous volume change at the orientational-ordering transition in solid <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">C</mi></mrow><mrow><mn>60</mn></mrow></msub></mrow></math></span>

Paul A. Heiney; Gavin B. M. Vaughan; John E. Fischer; Nicole Coustel; David E. Cox; John R. D. Copley; D. A. Neumann; W. A. Kamitakahara; Kathleen M. Creegan; Donald M. Cox; John P. McCauley, Jr; Amos B. Smith, III

doi:10.1103/PhysRevB.45.4544

Rapid Communication

Discontinuous volume change at the orientational-ordering transition in solid $C_{60}$

Paul A. Heiney, Gavin B. M. Vaughan, John E. Fischer, Nicole Coustel, David E. Cox, John R. D. Copley, D. A. Neumann, W. A. Kamitakahara, Kathleen M. Creegan, Donald M. Cox, John P. McCauley, Jr., and Amos B. Smith, III

Phys. Rev. B 45, 4544(R) – Published 15 February 1992

Abstract

X-ray and neutron-diffraction measurements have been used to study the evolution of the lattice parameter of solid $C_{60}$ through the orientational-ordering transition. The lattice parameter jumps by +0.044±0.004 Å on heating, indicating a strongly first-order transition. The average isobaric volume thermal-expansion coefficient both above and below the transition is 6.2±0.2× $10^{- 5}$ $K^{- 1}$ . We observe phase coexistence over a 5-K range, but little if any hysteresis.

Received 12 November 1991

DOI:https://doi.org/10.1103/PhysRevB.45.4544

Authors & Affiliations

Paul A. Heiney and Gavin B. M. Vaughan

Department of Physics and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104

John E. Fischer and Nicole Coustel

Department of Materials Science and Engineering and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104

David E. Cox