Investigations of the zero-field splitting with the local tilting angle τFe3+ for Fe3+ in ZnGeP2 crystal

The axial zero-field splitting parameter D for Fe3+ at Ge4+ site of ZnGeP2 chalcopyrite semiconductor is calculated using the method based on the dominant spin–orbit coupling mechanism. In the calculation, the impurity-induced local tilting angle of anion tetrahedron, which is much larger than the corresponding tilting angle in the host ZnGeP2 crystal, is applied. The results indicate the negative sign of D, whereas the magnitude of D is explained reasonably, and the large tilting angle is further confirmed for Fe3+ in ZnGeP2 crystal.