论文信息 - Structural and magnetic properties of Cr1+x(Se1−yTey)2 compounds

Structural and magnetic properties of Cr1+x(Se1−yTey)2 compounds

Abstract The structural and magnetic properties of Cr 1+ x (Se 1− y Te y ) 2 having a NiAs structure has been studied for (1+ x )=1.27, 1.32 and 1.36 and y =0.75 by means of the Korringa–Kohn–Rostoker (KKR) band structure method. The sub-stoichiometry and the disorder on the chalcogenide sub-lattice has been treated by means of the coherent potential approximation (CPA) alloy theory. From total energy calculations a preferential site occupation on the Cr sub-lattice was found together with an antiparallel alignment of the magnetic moments on the two inequivalent Cr layers. The magnetic properties at finite temperature has been studied by means of Monte Carlo simulations on the basis of a classical Heisenberg Hamiltonian and the exchange coupling parameters calculated from first principles. This approach allowed to determine the critical temperature in good agreement with experiment.

Wolfgang Bensch | Hubert Ebert | S. Mankovsky | S. Polesya | Z.-L. Huang

[1] H. Ebert,et al. Crystal structures, unusual magnetic properties and electronic band structures of Cr5−xTixTe8 , 2005 .

[2] R. D. Groot,et al. Band-structure calculations, and magnetic and transport properties of ferromagnetic chromium tellurides (CrTe, Cr3Te4, Cr2Te3) , 1989 .

[3] Josef Kudrnovsky,et al. Ab initio calculations of exchange interactions, spin-wave stiffness constants, and Curie temperatures of Fe, Co, and Ni , 2001 .

[4] P. Bruno,et al. Ferromagnetism in diluted magnetic semiconductors: A comparison between ab initio mean-field, RPA, and Monte Carlo treatments , 2003 .

[5] V. A. Gubanov,et al. Local spin density functional approach to the theory of exchange interactions in ferromagnetic metals and alloys , 1987 .

[6] S. H. Vosko,et al. Accurate spin-dependent electron liquid correlation energies for local spin density calculations: a critical analysis , 1980 .

[7] H. Ebert,et al. Anion substitution effects on structure and magnetism in the chromium chalcogenide Cr5Te8—Part I: Cluster glass behavior in trigonal Cr(1+x)Q2 with basic cell (Q=Te, Se; Te:Se=7:1) , 2004 .