Samatham S Shanmukharao, Patel Akhilesh Kumar, Mishra Ashish Kumar, Lukoyanov Alexey V, Gramateeva Lyubov N, Lakhani Archana, Vedachalaiyer Ganesan, Gopinatha Warrier Suresh Krishnawarrier
Department of Physics, Chaitanya Bharathi Institute of Technology, Gandipet, Hyderabad 500075, India.
Magnetic Materials Laboratory, Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.
ACS Omega. 2022 May 17;7(21):18110-18121. doi: 10.1021/acsomega.2c01571. eCollection 2022 May 31.
We report a comprehensive investigation of MnNiFeGe Heusler alloy to explore its magnetic, caloric, and electrical transport properties. The alloy undergoes a ferromagnetic transition across ∼ 212 K and a weak-antiferromagnetic transition across ∼ 180 K followed by a spin-glass transition below ∼ 51.85 K. A second-order phase transition across 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 from magnetization and specific heat data. The frequency dependent cusp in χ() along with the absence of a clear magnetic transition in specific heat () and resistivity ρ() establish the spin glass behavior below . 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.
我们报告了对MnNiFeGe赫斯勒合金的全面研究，以探索其磁、热和电输运性质。该合金在约212 K处经历铁磁转变，在约180 K处经历弱反铁磁转变，随后在约51.85 K以下发生自旋玻璃转变。通过临界指数研究以及磁熵和磁电阻的普适标度，证实了在具有短程和长程混合磁相互作用的情况下发生的二级相变。从磁化强度和比热数据可以明显看出，在 处存在弱一级相变。χ()中与频率相关的尖峰，以及比热()和电阻率ρ()中没有明显的磁转变，证实了 以下的自旋玻璃行为。密度泛函计算表明，存在混合铁磁和反铁磁相互作用，且铁磁耦合占主导，这从大的正魏斯温度、磁饱和以及负磁熵和磁电阻中得到了实验验证。
