在三角晶格反铁磁体中，量子自旋液体态的产生条件与三角晶格的形变程度之间是否存在关联一直是一个关键科学问题。本项目以M2(OH)3X（M=Cu,Ni,Co;X=Cl,Br,I）三角晶格体系为研究对象，以这些材料的基态磁性、磁转变以及磁激发为主要研究内容，依托中科院强磁场科学中心（≥20T）拟开展以下工作：1）通过元素替代和施加压力，改变三角晶格的形变，利用常规磁场下的磁性和比热以及强磁场超高压下的磁化率测量，研究基态磁性与物理/化学压力的关系；2）在超强磁场下对磁有序材料进行各向异性的磁性测量，探索高场下的量子相变，建立完整的温度—磁场相图；3）利用强磁场下的比热和核磁共振手段，获得有关磁激发和能隙方面的量子信息。通过以上实验研究，揭示几何阻挫、量子涨落、晶格形变、交换作用、磁各向异性等对材料的基态磁性、磁转变和磁激发的重要影响，争取在材料探索和新奇量子现象方面取得新进展。

One key issue in the triangular lattice antiferromagnetis is the relationship between the emergance of quantum spin liquid and the lattice deformation. Under the support of High Magnetic Field Laboratory of CAS (≥ 20 T), this project plans to study the magnetic ground states, magnetic transitions, and magnetic excitations of triangular lattice compounds M2(OH)3X (M=Cu,Ni,Co;X=Cl,Br,I). The main research includes: 1) studying the effect of physical/chemical pressure on the ground state magnetism via altering the lattice deformation by replacing element and applying pressure, using magnetic susceptibility and specific heat characterization under conventional magnetic fields and high-pressure magnetic susceptibility measurement under high magnetic fields; 2) exploring quantum phase transitions in high magnetic fields by performing anisotropic magnetization measurement on the magnetically ordered compounds and establishing complete temperature-field phase diagram; 3) investigating the magnetic excitations and spin gap using specific heat and nuclear magnetic resonance techniques in high magnetic fields. Based on the above investigations, we try to uncover the significant influence of geometrical frustration, quantum fluctuations, lattice deformation, spin exchange, magnetic anisotropy on the quantum magnetism and magnetic excitations, and make great progress in finding new materials and novel quantum phenomena.