Eur. Phys. J. B 15, 657-663 (2000)
https://doi.org/10.1007/s100510051169

Single crystal study of the one dimensional Ca₃Co₂O₆ compound: five stable configurations for the Ising triangular lattice

Laboratoire CRISMAT, ISMRA et Université de Caen, 6 boulevard du Maréchal Juin, 14050 Caen Cedex, France

Received: 7 December 1999
Published online: 15 June 2000

Abstract

Single crystals of the one-dimensional phase Ca₃Co₂O₆ of several mm length have been grown. The magnetic study of such a crystal confirms the previous observations on polycrystalline samples: it consists of a triangular lattice of ferromagnetic [Co₂O₆] chains ( K) antiferromagnetically coupled ( K). The dynamic of these chains array, probed by AC susceptibility, is very slow as shown from the large shift of the freezing temperature from 12 K to 16.5 K as the excitation frequency increases by three orders of magnitude (10⁰ to 10³ Hz). The origin of this effect is believed to be the result of different arrangements with close energies for the chain ferromagnetic moments on the triangular lattice. Five stable magnetic configurations have been evidenced by the magnetization as a function of applied field curves registered at 2 K. Their relative magnetizations correspond to m=1/4, 1/2, 1, 2, 3 where m=3 represents the ferromagnetic ordering of three chains on the same triangle, each chain having a m=1 magnetization. A magnetic phase diagram is finally proposed.