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The ternary full Heusler alloy nanoparticle Fe2CrSi compounds were prepared using mechanical alloy method. The as-prepared sample was observed as amorphous in nature and further increases various annealing temperatures (like 700 °C, 800 °C, and 900 °C) in nitrogen gas atmosphere for 5 h in tubular furnace using quartz tube. X-ray diffraction studies confirmed the formation of Cu2MnAl-type structure instead of the conventional L21 disordered structure. Through Williamson-Hall plot (W-H plot), the uniform deformation model was used to get low value of strain-induced broadening. In the surface morphology, elemental composition studies were carried out using HRSEM with EDS. The presence of Fe2CrSi with the particle size of ~ 35 nm was also observed using high-resolution scanning electron microscopy and elemental composition study confirmed the presence of Fe, Cr, and Si. The magnetic properties of Fe2CrSi nanoparticles were studied showing ferromagnetic behavior and low coercivity of soft magnetic nature. Half metallic ferromagnetic Heusler alloys have wide range of applications from medical imaging to data storage for its profound performance on spintronics. [ABSTRACT FROM AUTHOR]

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 Eg = 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. [ABSTRACT FROM AUTHOR]

Fe2CoSn Heusler alloy nanoparticles were synthesized using co-precipitation method. The prepared samples were annealed at various temperatures (700 °C, 750 °C, 800 °C, 850 °C, and 900 °C) in N2 atmosphere. The structural properties of Fe2CoSn Heusler alloy nanoparticles were analyzed using powder X-ray diffraction techniques. The structure of the Fe2CoSn Heusler alloy nanoparticles was found to be FCC superlattice of L21 disorder structure. The grain size of Fe2CoSn Heusler alloy nanoparticles was found to be 4.82 nm for 800 °C annealed samples and it gets increased for high annealing temperatures. Dislocation density was calculated to be 4.304 × 1016 m−2 for 800 °C annealed samples with low coercivity, low exchange bias, high susceptibility, and high saturation values. [ABSTRACT FROM AUTHOR]

Fe2CoSi based Heusler alloy thin films are deposited on single crystal Si (111) substrate at different substrate temperatures varying from room temperature to 600 °C using ultrahigh vacuum DC magnetron sputtering. Structural analysis of the prepared thin films is carried out using GI-XRD measurement and it conform ordered L21 crystal structure of the films deposited at 450 °C and above. The atomic force microscopic (AFM) images of Fe2CoSi thin films exhibiting 3D-like growth on Si (111) substrate at varying temperatures. The magnetic property of the thin films is studied using vibrating sample magnetometer (VSM). At 450 °C of substrate temperature, the prepared thin film exhibits high saturation magnetization (Ms = 948 emu/cc) and low coercivity (Hc = 8 Oe). The self-energy magnetization of the film and its own field is very high, when the temperature of the substrate was maintained at 450 °C and switching field ratio for this film was obtained as ~ 0.9 due to its high crystallinity and atomic ordering. The electrical property of Fe2CoSi thin film is investigated using four-probe technique and a positive magnetoresistive behavior was observed for thin film deposited at a substrate temperature of 450 °C which indicates the possible half-metallic nature at room temperature. The enhanced magnetic and electrical properties obtained for the thin film prepared at 450 °C substrate temperature is highly suitable for spin -based device applications. [ABSTRACT FROM AUTHOR]