First-principles calculations and experimental studies on Cr2MnAl Heusler alloy nanoparticles for spintronics applications

In depth understanding of the magnetic, structural and electrical properties of Heusler alloys are crucial to achieve potential applications in spin-based device. Wherein, we report the synthesis of Cr₂MnAl Heusler alloy nanoparticles (NPs) via co-precipitation method and also demonstrated their transport properties. Interestingly X-ray analysis confirms the cubic phase of the synthesized Heusler alloy NPs and transmission electron microscopy (TEM) analysis reveals that the Cr₂MnAl as particle size of 10 ± 2 nm. Moreover, this particle size has adverse effect on symmetry of Cr₂MnAl Heusler alloy due to their higher surface to volume ratio that significantly changes their magnetic and electrical properties. These NPs exhibit soft ferromagnetic properties with a Curie temperature (Tc) of 25 K. Besides, resistivity measurements indicate the semiconducting nature and also we report the observation of anomalous Hall effect. In addition, we support our experimental results by studying the electronic and magnetic properties of alloy using first principle calculations. This density functional theory reveals that Cr₂MnAl has half metallic characteristics with high spin polarization. In light of above, this material can be used as intermediate layer to decouple the two ferromagnetic layers which acts as spin-polarized carriers in spin-based device.