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EXAFS investigation of the role of Cu on the chemical order and lattice distortion in L1 0 Fe–Pt–Cu thin films
Author(s) -
Laureti S.,
Brombacher C.,
Makarov D.,
Albrecht M.,
Peddis D.,
Varvaro G.,
D'Acapito F.
Publication year - 2014
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s1600576714019268
Subject(s) - extended x ray absorption fine structure , tetragonal crystal system , ternary operation , crystallography , magnetocrystalline anisotropy , anisotropy , materials science , lattice (music) , lattice constant , analytical chemistry (journal) , chemistry , crystal structure , absorption spectroscopy , diffraction , magnetic anisotropy , magnetization , physics , optics , chromatography , quantum mechanics , computer science , magnetic field , acoustics , programming language
This work presents an extended X‐ray absorption fine structure (EXAFS) characterization of ternary Fe–Pt–Cu alloys with different Cu content. The EXAFS measurements have been carried out at the Cu K α and Pt L III edges in order to describe the local environment around these elements in the Fe–Pt–Cu samples and to compare the structural evolution as a function of the Cu content. The EXAFS study, based on a substitutional model where the Cu atoms occupy Fe or Pt sites in the tetragonal structure, has been performed by using linear dichroism to enhance the sensitivity to differently oriented bonds and to gain a detailed description of the atomic environment. The study allowed the effects on the chemical order and lattice distortion induced by the Cu atoms to be distinguished experimentally. The determined positions of the Cu atoms in the chemically L1 0 ‐ordered face‐centred tetragonal lattice were correlated with the magnetic properties of Fe–Pt–Cu ternary alloys. In particular, the main effect of Cu atoms in the alloy is a linear reduction of the c / a ratio, while the nonmonotonic behaviour of the chemical order is consistent with the variation of the magnetocrystalline anisotropy.