A first-order antiferromagnetic-paramagnetic transition induced by structural transition in GeNCr3

A first-order antiferromagnetic (AFM)-paramagnetic (PM) phase transition has been confirmed by systematic magnetic measurements in GeNCr3, and it does not depend on the applied magnetic fields. Interestingly, a structural transition from space group P-421m to I4/mcm without breaking tetragonal symmetry appears around this AFM-PM transition temperature, which may be the driving force for the AFM-PM transition. Moreover, obvious exothermic and endothermic peaks in calorimetric measurements, a sharp peak of specific heat Cp(T), and a slope change of resistivity ρ(T) are also observed around structural transition temperature, indicating a strong coupling between structure and electrical as well as thermal properties.