Volume 78, Number 5, June 2007
Article Number 57005
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 22 May 2007
EPL, 78 (2007) 57005
DOI: 10.1209/0295-5075/78/57005

Magnetic structure and phase diagram in a spin-chain system: $\chem{Ca_{3}Co_{2}O_{6}}$

Y. B. Kudasov

Russian Federal Nuclear Center - VNIIEF, Sarov, 607188, Russia

received 11 February 2007; accepted in final form 25 April 2007; published June 2007
published online 22 May 2007

A transformation of the low-temperature magnetic structure governed by the 2D Ising model to the high-temperature honeycomb structure in the frustrated spin-chain compound Ca3Co2O6 is investigated. It is shown that the crossover between the two magnetic structures at 12 K arises from the entropy accumulated in the disordered chains. This interpretation is in an agreement with the experimental data. General rules for the phase diagram of frustrated Ising chain compounds are formulated.

75.25.+z - Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source X-ray scattering, etc.).
75.30.Kz - Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.).
75.50.Lk - Spin glasses and other random magnets.

© Europhysics Letters Association 2007