Magnetic phase diagram ofRbMnBr3investigated by specific heat and magnetocaloric effect

Abstract

We report on high-resolution measurements of the specific heat and magnetocaloric effect of the distorted triangular lattice antiferromagnet ${\mathrm{RbMnBr}}_3.$ Zero-field specific-heat data show a clear anomaly at $T_{c1\mathrm{}}=8.54\mathrm{}\hspace{0.5em}\mathrm{K}$ and a second shoulderlike anomaly about 35 mK above the first one. We study the evolution of these anomalies in applied external fields along the c axis and in the basal plane. We present a detailed magnetic phase diagram for $B\perp c$ for fields up to 7 T which is compared with earlier neutron scattering results and theoretical work.