Magnetic and magneto-elastic properties of a single crystal of TbB6

The magnetic and magneto-elastic properties of a single crystal of TbB6 are studied. In the ordered range metamagnetic behaviours are observed and com plex phase diagrams are determined for magnetic fields along fourfold and t hreefold directions. In the paramagnetic phase the third-order magnetic sus ceptibilities and the parastriction curves show anisotropic behaviour which could be accounted for by crystalline electric field (CEF) effects. A set of CEF parameters is proposed on the basis of the analysis of the experimen tal magnetic and quadrupolar susceptibilities. Though non-negligible, the d educed quadrupolar couplings are weak in comparison with those previously d etermined in PrB6.