Split Fermi Surface Properties of Noncentrosymmetric Compounds Fe2P, Ni2P, and Pd2Si.

We grew single crystals of Fe₂P, Ni₂P, and Pd₂Si with a noncentrosymmetric Fe₂P-type hexagonal structure, studied their Fermi surface properties by de Haas–van Alphen (dHvA) experiments, and compared results with energy band calculations. In paramagnets Ni₂P and Pd₂Si, the detected dHvA branches are well explained by the results of full potential linear augmented plane wave (FLAPW) band calculations. Because of the noncentrosymmetric crystal structure, the energy band splits, leading to two split Fermi surfaces. The angular dependences of dHvA frequencies for the main split Fermi surfaces are highly anisotropic, which is not observed for \(H\parallel [0001]\) but observed for \(H\perp [0001]\). The splitting energy due to the antisymmetric spin–orbit coupling is approximately estimated to be Δε \(\simeq \) 300 K in Ni₂P and 500 K in Pd₂Si for \(H\parallel [10\bar{1}0]\). This is a characteristic feature of the split Fermi surfaces in these compounds. In the case of a ferromagnet Fe₂P, only one kind of spin-split dHvA branch was observed. [ABSTRACT FROM AUTHOR]