Discovery of the Griffiths phase in the quaternary nitrides Ge1−xSnxNFe3

Abstract

AbstractWe report the Griffiths phase (GP) and transport behavior in the quaternary antiperovskite nitrides Ge1−xSnxNFe3 by a series of systematical magnetic susceptibility and thermoelectric behavior measurements. All the corresponding fitting exponent parameters λGP = 0.852 and 0.854 completely satisfy 0 ≤ λ ≤ 1 in GP regions for Ge0.7Sn0.3NFe3 and Ge0.8Sn0.2NFe3, respectively, indicating the different ferromagnetic concentrations in the system. An observed structural transition from distorted tetragonal structure (I4/mcm) to cubic antiperovskite (Pm3m) with increasing dopants should be responsible for the GP in Ge1−xSnxNFe3, which results in a magnetic phase transition from ferromagnetism (FM) to antiferromagnetism (AFM). Furthermore, the studies of electrical transport properties indicate that the Ge1−xSnxNFe3 series of compounds perform a Fermi liquid behavior at low temperature while the stronger electron‐phonon scatterings are found in the high‐temperature region. In addition, the intensive electron–electron correlation is also determined since much higher value of lattice thermal conductivity κl than the one of electronic thermal conductivity κe.