Magnetic Anisotropy and Berry-Phase Transport in Ferromagnetic NdGaGe Single Crystals

I will present results on single-crystal X-ray diffraction, magnetization, magnetic susceptibility, heat capacity, magnetotransport, and Hall transport measurements of NdGaGe (Neodymium–Gallium–Germanium) single crystals grown using a high-temperature Ga flux method. X-ray diffraction confirms a tetragonal structure, with refinements suggesting competition between centrosymmetric (I4₁/amd) and non-centrosymmetric (I4₁md) space groups. The possible lack of inversion symmetry can enhance Berry-curvature-driven transport phenomena. Magnetic and thermodynamic measurements show that NdGaGe is a ferromagnet with a Curie temperature of about 8.2 K and a strong easy axis along the c-direction. Magnetoresistance and magnetization are highly anisotropic, and Hall-effect measurements reveal a large anomalous Hall effect (AHE) below T_C. The dominance of the anomalous Hall term indicates a primarily intrinsic contribution from Berry curvature linked to spin–orbit coupling.