Successive spin-flop transitions of Neel-type antiferromagnet   Li$_2$MnO$_3$ single crystal with honeycomb-lattice
  We have carried out high magnetic field studies of single-crystalline Li$_2$MnO$_3$, a honeycomb lattice antiferromagnet. Its magnetic phase diagram was mapped out using magnetization measurements at applied fields up to 35 T. Our results show that it undergoes two successive meta-magnetic transitions around 9 T fields applied perpendicular to the ab-plane (along the c*-axis). These phase transitions are completely absent in the magnetization measured with field applied along the ab-plane. In order to understand this magnetic phase diagram, we developed a mean-field model starting from the correct Neel-type magnetic structure, consistent with our single crystal neutron diffraction data at zero field. Our model calculations succeeded in explaining the two meta-magnetic transitions that arise when Li$_2$MnO$_3$ enters two different spin-flop phases from the zero field Neel phase. 
K. Balamurugan, Sang-Hyun Lee, Jun-Sung Kim, Jong-Mok Ok, Youn-Jung   Jo, Young-Mi Song, Shin-Ae Kim, E. S. Choi, Manh Duc L...
cond-mat.str-el cond-mat.mtrl-sci