Griffiths phase-like behavior with compensated ferrimagnetism and spin valve effect in quaternary Heusler alloy CuNiCrAl

We present an experimental study of a new quaternary Heusler alloy CuNiCrAl (CNCA) with an emphasis on the effect of atomic structure on the magneto-transport characteristics. Detailed neutron diffraction (ND) data reveal that CNCA crystallizes in a mixed phase consisting of both cubic and tetragonal structures in the ratio 90.7:9.3. Rietveld refinement of X-ray diffraction (XRD) and ND data reveals that it exhibits B2 disorder in its cubic phase. Almost zero moment with negligible coercive field in dc magnetization suggests the fully compensated ferrimagnetic (FCF) nature. The dc susceptibility behavior at low temperatures (ZFC and FCC) indicates the complex magnetic interaction present at low temperatures. Additional analysis of dc susceptibility, specifically the deviation from the Curie-Weiss law along with the Arrott plots, reveals the presence of Griffiths-like behavior at room temperature. The lack of quadratic temperature dependence in the resistivity data at low temperatures indicates the half-metallic behavior. An unsaturated and asymmetric magnetoresistance is detected at 5 K, up to a magnetic field strength of 50 kOe, in both positive and negative fields. This implies the presence of spin valve-like features. Having multiple potential qualities in one system is rare, making CuNiCrAl a viable platform for many applications. [Display omitted] •Coexistence of cubic and tetragonal phases revealed by XRD and room temperature neutron diffraction.•Griffith’s phase observed close to room temperature.•Complex magnetic interactions with a fully compensated ferrimagnetic state is observed through dc magnetization.•Half-metallic behavior is observed at low temperatures.•Asymmetric behavior of MR indicates the presence of spin-valve like characteristics.