The pulsed high magnetic field facility and scientific research at Wuhan National High Magnetic Field Center

Wuhan National High Magnetic Field Center(WHMFC)at Huazhong University of Science and Technology is one of the top-class research centers in the world,which can offer pulsed fields up to 90.6 T with different field waveforms for scientific research and has passed the final evaluation of the Chinese government in 2014.This paper will give a brief introduction of the facility and the development status of pulsed magnetic fields research at WHMFC.In addition,it will describe the application development of pulsed magnetic fields in both scientific and industrial research.

Emerging in-plane anisotropic two-dimensional materials

Black phosphorus(BP)is a rapidly up and coming star in two-dimensional(2D)materials.The unique characteristic of BP is its in-plane anisotropy.This characteristic of BP ignites a new type of 2D materials that have low-symmetry structures and in-plane anisotropic properties.On this basis,they offer richer and more unique low-dimensional physics compared to isotropic 2D materials,thus providing a fertile ground for novel applications including electronics,optoelectronics,molecular detection,thermoelectric,piezoelectric,and ferroelectric with respect to in-plane anisotropy.This article reviews the recent advance in characterization and applications of in-plane anisotropic 2D materials.

Strain-sensitive ferromagnetic two-dimensional Cr_(2)Te_(3)

Searching for room temperature magnetic two-dimensional(2D)materials is a charming goal,but the number of satisfied materials is tiny.Strain can introduce considerable deformation into the lattice structure of 2D materials,and thus significantly modulate their intrinsic properties.In this work,we demonstrated a remarkable strain-modulated magnetic properties in the chemical vapor deposited Cr_(2)Te_(3) nanoflakes grown on mica substrate.We found the Curie temperature of Cr_(2)Te_(3) nanoflakes can be positively and negatively modulated under tensile and compressive strain respectively,with a maximum varied value of -40 and-90 K,dependent on the thickness of samples.Besides,the coercive field of Cr_(2)Te_(3) nanoflakes also showed a significant decrease under the applied strain,suggesting the decrease of exchange interaction or the change of the magnetization direction.This work suggests a promise to employ interfacial strain to accelerate the practical application of room temperature 2D magnetics.

Strong tunability of cooperative energy transfer in Mn2＋-doped （Yb3＋, Er3＋）/NaYF4 nanocrystals by coupling with silver nanorod array

Fluorescent rare-earth ions are useful for efficient energy transfer via multi- channels with different properties. Tuning these transfer processes in functional rare-earth materials has attracted considerable attention to satisfy the various demands of diverse practical applications. In this study, strong tunabilities of cooperative energy transfer and nonlinear upconversion emissions are realized using （Yb3＋, Er3＋）/NaYF4 nanocrystals with and without doped Mn2~ ions by adopting a plasmonic nanocavity composed of a silver nanorod array. The plasmon nanocavity can not only increase the energy transfer between Mn2＋ and （Yb3＋, Er3＋） but also significantly enhance the radiative emission. This reveals a prominent nonlinear gain in the nanocavity nanosystems. These observations suggest the prospective applications in the design and preparation of rare-earth nanocrystals with excellent tunabilities of multiple functionalities.

Optical spectroscopy study of Ca_3(Ru_(0.91)Mn_(0.09))_2O_7 single crystal in high magnetic fields

The magneto-optical spectrum, with magnetic fields up to 42 T, of double layered ruthenates Ca_3(Ru_(0.91)Mn_(0.09))_2O_7(CRMO) single crystal is studied. Both the temperature and magnetic field induced insulator-to-metal transitions(IMTs) are observed via magneto-optical properties of the crystal. The critical magnetic field(H//c) of IMT for CRMO is found to be as large as 35 T at 5 K. The fine structure of optical spectra identified the antiferromagnetic/ferro-orbital-ordering configurations of Ru 4d orbitals at low temperatures. Meanwhile, the configuration of orbital polarization of such double-layer CRMO single crystal is discussed. These results suggest that the orbital degree of freedom plays an important role in the field induced IMT of multi-orbital system.