Enhanced Magnetic Properties of Ni51Mn33.4In15.6 Heusler Alloy Nanoparticles

A systematic study of the size effect on the magnetic and structural properties of a Ni
₅₁
Mn
_33.4
In
_15.6
Heusler alloy converted to nanoparticles has been performed. We present new data to explain the enhanced magnetic properties of the nanostructured Heusler alloy synthesized through a high-energy ball-milling technique. The properties of the particles were characterized by X-ray diffraction, electron microscopy, and magnetometer techniques. Isothermal magnetic field variation of magnetization exhibits field hysteresis in bulk Ni
₅₁
Mn
_33.4
In
_15.6
alloy across the martensitic transition. As the size of the nanoparticles is reduced, there is an increase in the magnetization per unit of applied magnetic field, and a decrease in the coercivity as well as a substantial reduction in hysteresis.