Absence of magnetic order in dichloro [1,2-bis (diphenylphosphino) ethane] nickel²⁺ single crystal*

Dichloro [1,2-bis (diphenylphosphino) ethane] nickel2+ (NiCl2(dppe)) is an organic compound containing C26H24P2(dppe) molecules and Cl−, Ni2+ ions. The large-size NiCl2(dppe) single crystals with longest dimension of 4 mm were grown by the method of slow evaporation of organic solution. Single crystal x-ray diffraction spectrum indicates that the single crystal is of high quality. Magnetization results of the NiCl2(dppe) single crystals show an anisotropic paramagnetism behavior and diamagnetic background, which come from Ni2+ ions and benzene ring, respectively. However, according to the specific heat results with temperature down to 0.1 K and magnetic field up to 14 T, no expected field-induced quantum phase transition was observed in NiCl2(dppe) single crystals.