Magnetocaloric properties and critical behavior of high relative cooling power FeNiB nanoparticles

Abstract

Low cost magnetocaloric nanomaterials have attracted considerable attention for energy efficient applications. We report a very high relative cooling power (RCP) in a study of the magnetocaloric effect in quenched FeNiB nanoparticles. RCP increases from 89.8 to 640 J kg À1 for a field change of 1 and 5 T, respectively, these values are the largest for rare earth free iron based magnetocaloric nanomaterials. To investigate the magnetocaloric behavior around the Curie temperature (T C ), the critical behavior of these quenched nanoparticles was studied. Detailed analysis of the magnetic phase transition using the modified Arrott plot, Kouvel-Fisher method, and critical isotherm plots yields critical exponents of b ¼ 0.364, c ¼ 1.319, d ¼ 4.623, and a ¼ À0.055, which are close to the theoretical exponents obtained from the 3D-Heisenberg model. Our results indicate that these FeNiB nanoparticles are potential candidates for magnetocaloric fluid based heat pumps and low grade waste heat recovery. V

Magnetocaloric Properties of Fe-Ni-Cr Nanoparticles for Active Cooling

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“…However, the narrow working temperature span and large magnetic and thermal hysteresis in FOTM limit real-world applications5132728. The magneto-structural transition is often associated with field and temperature hysteresis, which reduce maximum operating frequency.…”

Direct and indirect measurement of the magnetocaloric effect in bulk and nanostructured Ni-Mn-In Heusler alloy

“…This is in agreement with other literatures on the synthesis of nanoparticles through high energy ball milling technique. 28,[32][33][34][35][36] Resultant powder was annealed at 400 • C for 6 h to remove internal stresses which were created during the milling process.…”

Structural and Magnetic Studies of the Fe-Co-Zr-Mo-W-B Amorphous Alloy

“…There are three main factors allowing to estimate the potential of magnetocaloric materials: the magnetic entropy change (∆S M ), the adiabatic temperature change (∆T ad ) and the relative cooling power (RCP) [8]. An ideal magnetic refrigerant material has to possess large values of both ∆S M and ∆T ad as well as high RCP around room temperature at a low magnetic field [9].…”