Document Type

Article

Publication Title

Physical Review B

Abstract

Mossbauer spectra for '"Au in Au metal and the intermetallic compounds AuAl„AuGa„AuIn„and AuSb2 have been obtained for the temperature range 4.2 to 95'K. The isomer shifts for these absorbers with respect to a ' Au in Pt source are —1.223(2) [Au metal], + 2.288(12) [AuSb2], + 3.489(4) [AuIn2], +4.450(11) [AuGa, ], and +.5.967(5) [AuAl, ] in units of mm/sec. The difference in isomer shifts (alloy-Au-metal) may be interpreted in terms of an increasing electron charge density at the Au nucleus in the alloys as compared to that of Au metal. When volume changes for the alloys with respect to the pure metal are taken into account, we conclude that approximately one 6s-like electron is transferred to the Au in each of the alloys. The Au isomer shifts in the alloys are only weakly temperature dependent and this is consistent with the ' 'Au Knight-shift measurements with three of these alloys. The recoilless fractions have been measured as a function of temperature and parametrized within the framework of the Debye model. We obtain at 4.2'K, f(AuGa2) 13.4% (SD —140'K), f(AuSb2) 15.1% {O~ —152'K), f{AuA12) —15.7% (0& —152'K), f{AuA12) —21.9% (8~ —192 'K).

First Page

1835

Last Page

1839

DOI

10.1103/PhysRevB.11.1835

Publication Date

3-1-1975

Included in

Physics Commons

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