The ternary full Heusler alloy Mn₂CoAl nanoparticles were synthesized by using co-precipitation technique. The as-prepared sample was observed for amorphous nature and further increased at various annealing temperatures (like 700 °C, 800 °C and 900 °C) in argon gas atmosphere for 5 h. X-ray diffraction studies were performed, and the pattern confirms the formation of Hg₂CuTi-type structure of the XA or Xα disorder structure. Williamson-Hall plot (W-H plot) was used to find the uniform deformation model so as to get low value of strain-induced broadening. The presence of Mn₂CoAl with the particle size ≈ 50 nm was obtained from high-resolution scanning electron microscopy (HR-SEM), and the elemental analysis study confirms the presence of Mn, Co, and Al. UV-Visible absorption spectrum shows the wide absorption peak at 470 nm and the estimated band gap energy value at E_g = 0.8 eV (from Tauc plot) for 900 °C annealed sample. Synthesized Mn₂CoAl nanoparticles induced ferromagnetic behavior due to composition deviation and as a result displayed low coercivity of soft magnetic behavior. Half-metallic ferromagnetic Heusler alloys have a wide range of applications from medical imaging to data storage, and also it has profound spintronics applications.

中文翻译：

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用于自旋电子学的半金属Mn 2 CoAl Heusler合金纳米粒子的软铁磁性能

采用共沉淀技术合成了三元完整的Heusler合金Mn ₂ CoAl纳米粒子。观察所制备的样品的非晶态性质，并在氩气气氛中在各种退火温度（例如700°C，800°C和900°C）下进一步升高5 h。进行了X射线衍射研究，并且该图案证实了XA或Xα无序结构的Hg ₂ CuTi型结构的形成。使用威廉姆森-霍尔图（WH图）来找到均匀变形模型，从而获得较低的应变诱发展宽值。Mn ₂的存在通过高分辨率扫描电子显微镜（HR-SEM）获得了粒径约为50 nm的CoAl，并且元素分析研究证实了Mn，Co和Al的存在。紫外可见吸收光谱显示 900°C退火的样品在470 nm处有宽吸收峰，在E _g = 0.8 eV处（根据Tauc图）估计的带隙能量值。合成的Mn ₂ CoAl纳米颗粒由于组成偏差而引起铁磁行为，因此显示出低的软磁行为矫顽力。半金属铁磁Heusler合金具有广泛的应用范围，从医学成像到数据存储，还具有广泛的自旋电子学应用。