Electronic structure and local magnetism of 3d–5d impurity substituted CeFe2. (22nd March 2016)

• Record Type: Journal Article
• Authors: Das, Rakesh; Das, G P; Srivastava, S K
• Is Part Of: Journal of physics. Volume 49:Number 16(2016)
• Publication Date: 2016-03-22
• Subjects: electronic structure -- local magnetism -- impurity -- laves phase; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/49/16/165004
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: We present here a systematic first-principles study of electronic structure and local magnetic properties of Ce[Fe0.75 M0.25 ]2 compounds, where M is a 3 d, 4 d or 5 d transition or post-transition element, using the generalized gradient approximation of the density functional theory. The d – f band hybridizations existing in CeFe2 get modified by the impurity M in an orderly manner across a period for each impurity series: the hybridization is strongest for the Mn group impurity in the period and gets diminished on either side of it. The weakening of the d – f hybridization strength is also associated with a relative localization of the Ce 4 f states with respect to the delocalized 4 f states in CeFe2 . The above effects are most prominent for 3 d impurity series, while for 4 d and 5 d impurities, the hybridizations and relocalizations are relatively weak due primarily to the relatively extended nature of 4 d and 5 d wavefunctions. The Ce local moment is found to decrease from the CeFe2 value in proportion to the strength of relocalization, thus following almost the same orderly trend as obeyed by the d – f hybridization. Further, depending on the way the spin-up and spin-down densities of states of an impurity shift relative to the Fermi energy, the impurity local moments are highest for Mn or Fe group, reduce on either side, become zero for Ni to Ga, and are small but negative for V and Ti. The Ce hyperfine field is found to follow the M local moment in a linear fashion, and vice–versa.