材料期刊网

The antiferromagnetic phenomena of the heterodinuclear Cu-F-Mn clusters in K2CuF4: Mn2+ and KZnF3: Cu2+- Mn2+ systems have been studied by the use of the heterodinuclear magnetic formula and the effective potential method. In our calculations two different models which are associated, respectively, with the elongated and the compressed Jahn-Teller distortion along the Cu-F-Mn direction have been taken for describing the located structures in KZnF3: Cu2+-Mn2+ system. It is demonstrated that the strong antiferromagnetic exchange interaction in KZnF3: Cu2+-Mn2+ which is about two times larger than that in K2CuF4:Mn2+ may be attributed to the Jahn-Teller compressed distortion in KZnF3:Cu2+-Mn2+. The theoretical values 2J = -143.4 and -59.9 cm(-1) are in good agreement with the experimental findings, 2J = 130 +/- 10cm(-1) in KZnF3:Cu2+ -Mn2+ and 2J = -52 +/- 2cm(-1) in K2CuF4:Mn2+ respectively. (C) 2001 Published by Elsevier Science B.V.