Field-Induced Magnetic Phase Transitions and Rich Phase Diagram of HoMnO3 Single Crystal

An extensive magnetization study in pulsed fields up to 62 T and at temperatures down to ~0.7 K has been performed on the single crystals of hexagonal manganite HoMnO3. For magnetic fields (H) applied along the c-axis, successive magnetic transitions below 10 T and a step-like transition at ~41 T are observed. The phase diagram for H//c is very complex and new phase boundaries are explored below 6 K. This phase diagram is compared with the early results derived from dielectric constant and neutron scattering measurements. For H//a, two magnetic transitions are found below 3 T dome-shaped and the phase diagram is reported for the first time. The variety of magnetic symmetries of the field-induced magnetic phases is discussed.