DOI: 10.1209/epl/i2002-00213-1


Europhys. Lett., 59 (3) , pp. 430-436 (2002)

The formation of orbital moments on iron impurities in Ag _1-xAu _x alloys

R. Kirsch^{1, 2}, M. J. Prandolini^{1, 2}, O. Beutler^{1, 2}, W. D. Brewer¹, M. Gruyters², J. Kapoor², D. Riegel², H. Ebert³ and S. Frota-Pessôa<sup>4

1</sup>  Fachbereich Physik, Freie Universität Berlin - 14195 Berlin, Germany
²  Hahn-Meitner-Institut Berlin GmbH - 14109 Berlin, Germany
³  Physikalische Chemie, Ludwig-Maximilians-Universität München 81377 Munich, Germany
⁴  Instituto de Física da USP - CP 66318, 05315-970 São Paulo, S.P. Brazil

(Received 14 March 2002; accepted in final form 7 May 2002)

Abstract
Using the high specificity and sensitivity of the in-beam perturbed -ray angular distribution method, we have investigated the magnetic behavior of very dilute ⁵⁴Fe probes in Ag _1-xAu _x alloys. The nuclear damping time and local susceptibility of Fe are found to depend strongly on its local environment, showing inhomogeneous line broadening as well as discrete magnetic responses due to the different configurations of Ag/Au nearest neighbors. The results can be understood with the aid of ab initio calculations of electronic structure, magnetic moments and hyperfine fields. They underline the central importance of orbital magnetism for understanding the experimental results.

PACS
71.15.Mb - Density functional theory, local density approximation, gradient and other corrections.
75.20.Hr - Local moments in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions.
76.80.+y - Mössbauer effect; other -ray spectroscopy.


© EDP Sciences 2002