Theoretical study of the magnetic properties of the CoCu2O3 compound

Abstract

In this paper we present a theoretical study of the magnetic properties of the ${\mathrm{CoCu}}_{2}{\mathrm{O}}_{3}$ compound. The magnetic effective exchange interactions and zeroth-field splitting were computed using ab initio methods, then the magnetic order and transition temperature were determined using classical Monte Carlo simulations. We showed that, unlike other members of the $A{\mathrm{Cu}}_{2}{\mathrm{O}}_{3}$ family, the presence of an additional magnetic atom, associated with a large folding of the puckered layers in the ($\stackrel{P\vec}{a}, \stackrel{P\vec}{b}$) directions, induces a magnetic pattern based on coupled three-leg ladders, quite different from the two-leg structural ladders. The propagation vector has been found to be $\stackrel{P\vec}{q}=(0,\frac{1}{2},\frac{1}{2})$. It is associated with a doubly degenerated ground state suggesting a doubling of the unit cell. The large ${\mathrm{Co}}^{2+}$-ion anisotropy was shown to be of crucial importance in the high transition temperature observed in this compound.