Bose-Einstein condensation of triplons in Ba3Cr2O8

By performing heat-capacity, magnetocaloric effect, torque magnetometry, and force magnetometry measurements up to 33 T, we have mapped out the T-H phase diagram of the S=1/2 spin dimer compound Ba3Cr2O8. We found evidence for field-induced magnetic order between Hc1=12.52(2) T and Hc2=23.60(5) T, with the maximum transition temperature Tc∼2.7 K at H∼18 T. The lower transition can likely be described by Bose-Einstein condensation of triplons …