An ab initio investigation of how residual resistivity can decrease when an alloy is deformed

S. Lowitzer¹, D. Ködderitzsch¹, H. Ebert¹, P. R. Tulip², A. Marmodoro³ and J. B. Staunton^3a

¹ Department Chemie, Physikalische Chemie, Universität München - Butenandstr. 5-13, 81377 München, Germany, EU
² School of Physics and Astronomy, University of Edinburgh - Edinburgh EH9 3JZ, UK, EU
³ Department of Physics, University of Warwick - Coventry CV4 7AL, UK, EU

^a j.b.staunton@warwick.ac.uk

Received: 5 July 2010
Accepted: 25 October 2010

Abstract

For a class of transition metal materials residual resistivity is observed to decrease when the materials are deformed and short-range order is removed. We investigate this counter-intuitive behavior with an ab initio theoretical study of the residual resistivity of several late transition metal-rich disordered alloys. The calculations are performed using the Korringa-Kohn-Rostoker (KKR) method applied to the Kubo-Greenwood formalism. The electronic effects arising from short-range ordering and clustering within the disorder are described using the non-local coherent-potential approximation (NL-CPA). We find a simple, general explanation of this K-state–like effect in terms of changes to the amplitude for d-electron hopping between majority late transition metal nearest-neighbor atoms at the Fermi energy.