Experimental and Theoretical Investigations of Fe-Doped Hexagonal MnNiGe

• Published in: ACS omega 2022-05, Vol.7 (21), p.18110-18121
• Main Authors: Samatham, S. Shanmukharao, Patel, Akhilesh Kumar, Mishra, Ashish Kumar, Lukoyanov, Alexey V., Gramateeva, Lyubov N., Lakhani, Archana, Vedachalaiyer, Ganesan, Gopinatha Warrier, Suresh Krishnawarrier
• Format: Article
• Language: English
• ISSN: 2470-1343; 2470-1343
• DOI: 10.1021/acsomega.2c01571

We report a comprehensive investigation of MnNi0.7Fe0.3Ge Heusler alloy to explore its magnetic, caloric, and electrical transport properties. The alloy undergoes a ferromagnetic transition across T C ∼ 212 K and a weak-antiferromagnetic transition across T t ∼ 180 K followed by a spin-glass transition below T f ∼ 51.85 K. A second-order phase transition across T C with mixed short and long-range magnetic interactions is confirmed through the critical exponent study and universal scaling of magnetic entropy and magnetoresistance. A weak first-order phase transition is evident across T t from magnetization and specific heat data. The frequency dependent cusp in χAC(T) along with the absence of a clear magnetic transition in specific heat C(T) and resistivity ρ­(T) establish the spin glass behavior below T f. Mixed ferromagnetic and antiferromagnetic interactions with dominant ferromagnetic coupling, as revealed by density functional calculations, are experimentally evident from the large positive Weiss temperature, magnetic saturation, and negative magnetic-entropy and magnetoresistance.