Many magnetic materials are of particular interest due to the field-induced magnetic phase transition. This physical phenomenon often occurs when the external magnetic field can compete with the exchange interactions, magnetic anisotropy, Dzyaloshinsky-moriya interaction, electron correlation etc. in these materials. A sufficient high magnetic field can change the spin or magnetic structure and therefore lead to a dramatic change of the magnetic moments in magnetization. For example, magnetic fields applied to an antiferromagnet induce a spin-flip or spin-flop transition. Particular interests are usually given to the low-dimensional frustrated materials where the quantum effect plays an important role and some novel quantum states often emerge with applying magnetic fields. Interesting examples are the experimental observations of fractional magnetization plateaus, Bose-Einstein condensation, supersolid state etc. in the so-called quantum magnets. Magnetic phase transitions also happen in materials such as multiferroics, magnetocaloric materials, magnetic alloy, strongly correlated system, etc, in which spins or magnetic moments correlate with other degrees of freedom (electron, orbit, lattice or domain) and gives rise to a diversity and complexity of the magnetic properties of the materials. Thus, pulsed high magnetic fields provide good opportunities to reveal the underlying magnetism and to explore novel quantum phases in these interesting magnetic materials. Fig.1 and Fig.2 show the high field studies of multiferroic CuFeO₂. One can observe a series of field-induced multi-step-like transitions, in which the critical fields are magnetic anisotropic and temperature-dependent. After systematical measurements, the high-field magnetic and multiferroic phase diagrams of CuFeO₂ have been carefully investigated. 

Fig. 1. High field magnetization and magnetic phase transitions in multiferroic CuFeO₂

Fig. 2. Magnetic field induced electric polarization in CuFeO₂