Time-resolved structural study of low-index surfaces of germanium near its bulk melting temperature

Journal Article · Wed Aug 15 04:00:00 EDT 2001 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.64.085410· OSTI ID:40277433

Zeng, Xinglin; Elsayed-Ali, H E

The structure of the low-index surfaces of germanium near its bulk melting temperature is investigated using 100-ps time-resolved reflection high-energy electron diffraction. The surface is heated by 100-ps laser pulses while a synchronized electron beam probes the structure. Ge(111) was observed to remain in its incomplete melting structure up to at least T{sub m}+134{+-}40 K when heated by a 100-ps laser pulse. Both the Ge(100) and Ge(110) surfaces are observed to melt near the bulk melting temperature when heated with 100-ps laser pulses. Because of the low-diffraction intensity-to-background ratio at high temperatures and because of the temperature uncertainty in the time-resolved experiments, we are unable to accurately identify the melting point of Ge(100) and Ge(110) when heated with a 100-ps laser pulse. The results, however, favor the lack of surface superheating of Ge(100) and, to some extent, Ge(110). The superheating of the incomplete melting state of Ge(111) could be due to the metallization of the top germanium bilayer and its interaction with the solid underneath causing an energy barrier sufficient to allow for transient surface superheating.

• Sponsoring Organization: (US)
• DOE Contract Number: FG02-97ER45625
• OSTI ID: 40277433
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 8 Vol. 64; ISSN 0163-1829
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTRON BEAMS
ELECTRON DIFFRACTION
GERMANIUM
LASERS
MELTING
MELTING POINTS
PROBES
REFLECTION
SUPERHEATING
TRANSIENTS