Abstract. For the geometrically frustrated spinel system CdV₂O₄ with V³⁺ (S = 1) that undergoes structural and magnetic transitions at T_c1 = 97 K, and may exhibit a transition to the antiferromagnetic state at T_c2 = 35 K, the crystal structures at 299 and 85 K have been determined with space groups Fdm and I4₁ /amd, respectively, by means of x-ray four-circle diffraction. At 85 K, the VO₆ octahedron is distorted due to the Jahn–Teller effect with contraction of the V–O bond along the tetragonal c axis, and the network of V ions is achieved by the linkage of a distorted V₄-tetrahedron block with two kinds of V–V bonds. On the basis of these structural properties, magnetic susceptibilities at temperatures between T_c1 and T_c2 are explained in terms of the tetragonally distorted pseudotetramer model.

Print publication: Issue 3 (29 January 2003)
Received 19 November 2002
Published 13 January 2003