Pressure dependences of band gaps and optical-phonon frequency in cubic SiC

Journal Article · Mon Jul 15 04:00:00 EDT 1991 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.44.1053· OSTI ID:5390816

Cheong, B H; Chang, K J ^[1]; Cohen, M L ^[2]

---

1. Department of Physics, Korea Advanced Institute of Science and Technology, P.O. Box 150, Cheongryang, Seoul, Korea (KR)
2. Department of Physics, University of California at Berkeley, Berkeley, CA (USA) Sciences Division, Lawrence Berkeley Laboratory, Berkeley, CA (USA)

The high-pressure behavior of the direct and indirect band gaps in zinc-blende-structure SiC is examined with use of self-consistent {ital ab} {ital initio} pseudopotential calculations. The fundamental band gap from {Gamma}{sub 15}{sup {ital v}} to {ital X}{sub 1}{sup {ital c}} is found to decrease linearly with pressure up to 200 kbar. This result disagrees with a recent experimental finding of strong sublinear behavior at pressures of 10 to 15 kbar. The linear pressure coefficients of the fundamental band gap and the transverse-optical-phonon frequency at the {Gamma} point in the Brillouin zone are in good agreement with measured values.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5390816
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 44:3; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
CARBIDES
CARBON COMPOUNDS
ENERGY GAP
MINERALS
PRESSURE DEPENDENCE
SILICON CARBIDES
SILICON COMPOUNDS
SPHALERITE
SULFIDE MINERALS
VERY HIGH PRESSURE