Structural, magnetic, magnetocaloric and magnetotransport properties in Ge doped Ni–Mn–Sb Heusler alloys

• Published in: Journal of magnetism and magnetic materials Vol. 324; no. 7; pp. 1267 - 1271
• Main Authors: Sahoo, Roshnee, Nayak, Ajaya K., Suresh, K.G., Nigam, A.K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2012; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity phenomena in semiconductors and insulators; Cross-disciplinary physics: materials science; rheology; Electronic transport in condensed matter; Exact sciences and technology; Exchange and superexchange interactions; Full Heusler alloy; Galvanomagnetic and other magnetotransport effects; Germanium; Heusler alloys; Magnetic properties; Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Magnetization; Magnetocaloric effect; Magnetocaloric effect, magnetic cooling; Magnetoresistance; Magnetoresistivity; Martensitic transformations; Materials science; Nickel base alloys; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Transition temperature; Magnetoresistance; Magnetocaloric effect; Full Heusler alloy; Nickel alloys; Magnetization; Impurity density; Antimony alloys; Martensitic transformations; Polycrystals; Arrott plot; Magnetocaloric effects; Manganese alloys; Heusler alloys; Transport processes; Germanium additions; Exchange interactions; Transition element alloys
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2011.11.025

The effect of Ge substitution on the magnetic, magnetocaloric and transport properties of Ni45Co5Mn38Sb12−xGex (x=0–3) has been investigated. The decrease in the exchange interaction brought by Ge substitution can be seen from the reduction in the magnetization of austenite phase and the increase in the martensitic transition temperature. The magnetocaloric effect and the magnetoresistance values are found to be quite sensitive to small changes in Sb/Ge ratio. Taking into account various properties, the present series seems to be a promising multifunctional system. ► The martensitic transition can be tuned to room temperature with a small change in Sb/Ge ratio. ► Substitution of Ge in Sb site in Ni45Co5Mn38Sb12 system leads to decrease in exchange interaction. ► Magnetization in austenite phase gradually decreases with increase in Ge concentration. ► The Hysteresis observed near martensitic transition for x=0 decreases considerably for x=3 in Ni45Co5Mn38Sb12−xGex system.