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1,2,4-Triazole Complexes VIII Magnetic properties of cobalt(II) (l,2,4-triazole)2(NCS)2, a quasi two-dimensional canted S = J antiferromagnet, with XY-type anisotropy

D. W. Engelfriet, W. L. Groeneveld,
Dept. Inorganic Chemistry, Gorlaeus Laboratoria,
Rijksumversiteit, Leiden, The Netherlands,
H. A. Groenendijk, J. J. Smit and G. M. Nap
Kamerlingh Onnes Laboratorium,
Rijksumversiteit, Leiden, The Netherlands
Z. Naturforsch. 35 a, 115-128 (1980);

[received November 22, 1979]

Co(trz)t(NCS)t has been investigated by means of magnetic susceptibility and magnetization measurements on single crystals in the temperature range from 1.1—300 K, heat capacity measurements from 1.5 —90 K, neutron powder diffraction at 1.2 K and ESR measurements on the Codoped Zn compound at 9 K. The compound appears to have two-dimensional structural and magnetic properties. A transition to an antiferromagnetically ordered state takes place at 7^=5.71 (Insusceptibility measurements along the three orthorhombic axes reveal a strongly anisotropic character. The b axis is found to be the preferred axis of antiferromagnetic alignment. The susceptibility data along b and the heat capacity results are in good agreement with the predictions for the quadratic layer, S=l, XY antiferromagnetic, with an intralayer exchange constant //=— 5.0(1)K. Below Tc the field dependent behaviour of the magnetization and the susceptibility along the a axis exhibits a transition at 1 kOe. Hidden canting is found to be present. The magnetic structure can be described by four sublattices with the magnetic moments lying in the a-b plane along directions that are at an angle of 7° with the 6 axis.

Introduction