Using a hydrothermal method, single crystals of Co4(BO 2)6O were synthesized. The DC susceptibility revealed a Curie-Weiss behavior at high temperature. The Weiss temperature was estimated at -190 K, showing very strong antiferromagnetic interactions. However, the susceptibility does not show any phase transitions down to 2 K, although there is a broad maximum in the vicinity of 14 K. This demonstrates an effect of the geometric frustration arising from the crystal structure based on isolated Co4 tetrahedral clusters. The magnetization curve exhibits an onset of a transition to higher magnetization state at around 5 T. The result suggests that the Co4 cluster has a nonmagnetic ground state with a spin gap and a magnetic field induces a transition into a magnetic state above the spin gap.
ASJC Scopus subject areas
- Physics and Astronomy(all)