Phase transitions in the liquid-vapor interface of dilute alloys of Bi in Ga: New experimental studies

Journal Article · Mon Jul 19 04:00:00 EDT 2010 · J. Chem. Phys.

DOI:https://doi.org/10.1063/1.1924544· OSTI ID:1008679

Li, Dongxu; Jiang, Xu; Yang, Bin; Rice, Stuart A ^[1]

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1. UC

We report the results of measurements of x-ray reflectivity and grazing incidence x-ray diffraction from the liquid-vapor interfaces of four dilute alloys of Bi in Ga with mole fractions x{sub Bi} = 0.0032, 0.0023, 0.00037, and 0.000037. The monolayer coverage of the alloys with x{sub Bi} = 0.0023, and x{sub Bi} = 0.00037 is about 0.85 and only very slightly temperature dependent. The monolayer coverage in the lowest-concentration alloy, with x{sub Bi} = 0.000037, ranged from 0.82 at 29 C to 0.58 at 110 C. In none of these alloys, down to the lowest temperature used, 29 C, can we find any evidence for crystallization of the Bi monolayer that segregates as the outermost stratum of the liquid-vapor interface. Drawing on theoretical arguments we propose that the transitions inferred from the second-harmonic generation and plasma generation studies of dilute Bi in Ga alloys are from the liquid state to the hexatic state of the Bi monolayer. The data for the alloy with x{sub Bi} = 0.000037 suggest that near 80 C there is a disordered phase-to-disordered phase transition.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: USDOE
• OSTI ID: 1008679
• Journal Information: J. Chem. Phys., Journal Name: J. Chem. Phys. Journal Issue: (22) ; 2005 Vol. 122; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
CRYSTALLIZATION
DILUTE ALLOYS
HARMONIC GENERATION
PLASMA
REFLECTIVITY
X-RAY DIFFRACTION