Calculation of exchange constants in manganese ferrite ( MnFe 2 O 4 )
نویسندگان
چکیده
The exchange constants and electronic structure of manganese ferrite (MnFe2O4) were calculated using Becke’s density functional. The total exchange energy consists of Hartree–Fock (HF) and Becke’s density functional terms. We introduced one parameter w as the weight of HF’s contribution. We also introduced a parameter a to scale the radial part of the 3d wave functions of Fe ions. By varying w and a the calculated exchange constants were quantitatively fitted to the experimental values of a spinel ferrite for the first time. Direct (d–d) and indirect (d–p–d) hopping are controlled by the parameters w and a. r 2003 Elsevier B.V. All rights reserved. PACS: 75.50.Gg; 75.30.Et; 71.15.Mb
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