Study of Magnetic Phase Transition and Spin Frustration in Cobalt Aluminium Oxide Materials based on High Temperature Series Expansions Model

Abstract

The magnetic properties of CoAl_2−2xCo_2xO₄ for 0 ≤ x ≤ 1 are studied. The values of the nearest neighbour (J₁), next‐nearest neighbour (J₂), intra‐plane (J_aa) and inter‐plane (J_ab,J_ac) exchange interactions are calculated by the mean field theory for ordered region and by the probability law adapted of the nature of dilution problem in A‐spinel lattice in spin glass region. The high‐temperature series expansions have been applied in the CoAl_2−2xCo_2xO₄ systems, combined with the Padé approximants method, to determine the Néel temperature T_N (K) or freezing temperature T_SG (K) in the range 0 ≤ x ≤ 1. The critical exponents associated with the magnetic susceptibility (y) and the correlation lengths (v) are deduced in the range ordered 0.3 ≤ x ≤ 1. The obtained values of y and v are insensitive to the dilution ratio x and may be compared with other theoretical results based on 3D Heisenberg model.

Citation

Masrour, R. and Hamedoun, M. (2009), "Study of Magnetic Phase Transition and Spin Frustration in Cobalt Aluminium Oxide Materials based on High Temperature Series Expansions Model", Multidiscipline Modeling in Materials and Structures, Vol. 5 No. 3, pp. 301-306. https://doi.org/10.1163/157361109789017023