Electronic study of FeTi, CoTi, and NiTi alloys: bulk, surfaces, and interfaces

Abstract

The full-potential linearized augmented plane waves (FP-LAPW) method within the generalized gradient approximation (GGA) is applied to determine the electronic properties of the equiatomic alloys B2-MTi (M = Fe, Co, Ni). Detailed analysis is devoted to the NiTi austenic, premartensic, and martensic phases. The martensic transformation (MT) occurs from the austenic B2 (CsCl structure) to the monoclinic B19' phase upon cooling. Spin-polarized slab calculations are carried out to study the FeTi(001), CoTi(001), and NiTi(001) surfaces and the FeTi/CoTi, FeTi/NiTi, and CoTi/NiTi interfaces. The stability mechanism of the interface is related to the calculated ideal work of adhesion. The corresponding electronic structure and local magnetic moments of the surface, sub-surface, and central layers are also given. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)