Search

The strong coupling of the spin and lattice subsystem exactly across the room-temperature region is observed in (MnNiSi)0.66(Fe2Ge)0.34 alloy which leads to a substantial change in magnetocaloric parameters. Substitution of Fe2Ge (Ni2In-type hexagonal symmetry) compound helps to distort the low temperature ferromagnetic phase and stabilize the high temperature paramagnetic phase near the room-temperature region. A large value of isothermal magnetic entropy change (ΔSM) of -13.67 J/kg-K at 300 K and relative cooling power (RCP) of 169.5 J/kg is observed for the (MnNiSi)0.66(Fe2Ge)0.34 alloy for a low magnetic field change of 30 kOe. Near room-temperature MST temperature and obtained large value of isothermal magnetic entropy change with large relative cooling power make the investigated (MnNiSi)0.66(Fe2Ge)0.34 alloy suitable for room-temperature solid state cooling applications. [ABSTRACT FROM AUTHOR]

Ferromagntic Fe2MnSi0.5Al0.5 heusler alloy has been studied here by analyzing its magnetic properties. To obtain the higher para to ferro magnetic transition temperature i.e. Curie temperature from the existing value of the parent compound, this particular compound has been chosen and, its critical exponent analysis has been done as there is no unique model for the 3d transition magnetic alloys to define their nature of phase transition. It has been observed that the material exhibit its Curie temperature at 225K and the Arrott plot technique employed here for obtaining Curie temperature also suggests that the magnetic phase transition observed here is of 2nd order. The critical exponent values 𝑖. 𝑒. 𝛽 = 0.49, 𝛾 = 1.001 𝑎𝑛𝑑 𝛿 = 3.04 are closely matching with theoretical Mean field value which indicates the existence of long range ferromagnetic ordering in the sample. [ABSTRACT FROM AUTHOR]