A facile method to grow crystals of the cobalt tellurite multiferroic material Co3TeO6

Abstract

The multiferroic material cobalt tellurite (Co₃TeO₆) exhibits complex magnetic transitions and magnetoelectric coupling properties. Chemical transport reactions to grow single crystals of Co₃TeO₆ require expensive PtCl₂ as the transport agent. Here, a convenient method was developed by utilizing ionic conductor polymorphs of Na₂Co₂TeO₆ as the precursor. Single crystals, as long as one centimeter, were successfully grown by heating a mixture of Na₂Co₂TeO₆ and MoO₃ in a sealed alumina crucible. The crystal quality was validated by single-crystal X-ray diffraction and scanning electron microscopy. The probable reaction mechanism was established and the by-products of Na₂MoO₄ and Na₂TeO₄ were observed by energy-dispersive X-ray spectroscopy. The complicated spin lattice was investigated and a unique Archimedean T11-related lattice constructed by Co2, Co3 and Co5 was proposed. Moreover, anisotropic magnetic susceptibilities under various fields and magnetization were also determined. This work may pave the way for the crystal growth of transition-metal tellurites by employing a relatively polynary complex as a precursor.