Magnetic and magnetocaloric properties of Pr2-xNdxFe17 ribbons

Bishnu Dahal,Shah Valloppilly,Wenyong Zhang,Ralph Skomski,Thomas Ott,Parashu Kharel,David Sellmyer

doi:10.1063/1.5080105

Abstract

The structural, magnetic and magnetocaloric properties of Fe deficient Pr2-xNdxFe17 (x = 0.5, 0.7) alloys prepared by arc-melting and melt-spinning have been investigated. The room temperature x-ray diffraction patterns show that the samples are nearly single-phase and crystallize in the rhombohedral Th2Zn17-type crystal structure. The Curie temperatures determined from the thermomagnetic curves are 302 K and 307 K for Pr1.5Nd0.5Fe17 and Pr1.3Nd0.7Fe17, respectively. The peak magnetic entropy change and the relative cooling power at field change of 50 kOe are 3.01 J/kgK and 345 J/kg for Pr1.5Nd0.5Fe17, and 4.31 J/kgK and 487 J/kg for Pr1.3Nd0.7Fe17, respectively. The absence of magnetic and thermal hysteresis with relatively high cooling efficiency suggests that the alloys have potential for magnetic refrigeration.

Highlights

Magnetic refrigeration is expected to become an alternative to the current gas-compression cooling system with advantages such as high energy efficiency, low manufacturing and maintenance costs, and use of environment friendly solid state materials.1–6 The magnetic refrigeration (MR) is based on the magnetocaloric effect (MCE), where a magnetic material shows thermal response to an external magnetic field.7 The MCE is measured either in terms of the magnetic entropy change (∆SM) in an isothermal process or in terms of the temperature change (∆Tad) in an adiabatic process
Development of magnetic materials with large ∆SM and ∆Tad over a broad temperature range near room temperature is crucial for the advancement of magnetic refrigeration technology
Our goal is to develop intermediate compositions with Curie temperature very close to room temperature, starting from Pr2Fe1715 and Nd2Fe17.16,17 Since the Tc of Pr2Fe17 is somewhat lower than room temperature (283 K) and that of Nd2Fe17 is somewhat higher than room temperature (340 K), it is possible to adjust the Tc of Pr2-xNdxFe17 near room temperature by adjusting the elemental composition

Summary

Introduction

Magnetic refrigeration is expected to become an alternative to the current gas-compression cooling system with advantages such as high energy efficiency, low manufacturing and maintenance costs, and use of environment friendly solid state materials. The magnetic refrigeration (MR) is based on the magnetocaloric effect (MCE), where a magnetic material shows thermal response to an external magnetic field. The MCE is measured either in terms of the magnetic entropy change (∆SM) in an isothermal process or in terms of the temperature change (∆Tad) in an adiabatic process. Magnetic refrigeration is expected to become an alternative to the current gas-compression cooling system with advantages such as high energy efficiency, low manufacturing and maintenance costs, and use of environment friendly solid state materials.. The magnetic refrigeration (MR) is based on the magnetocaloric effect (MCE), where a magnetic material shows thermal response to an external magnetic field.. The MCE is measured either in terms of the magnetic entropy change (∆SM) in an isothermal process or in terms of the temperature change (∆Tad) in an adiabatic process. Development of magnetic materials with large ∆SM and ∆Tad over a broad temperature range near room temperature is crucial for the advancement of magnetic refrigeration technology.. The value of ∆SM depends on the rate at which magnetization changes with temperature (∂M/∂T). Large values of ∆SM are obtained near phase transitions. Materials undergoing magnetostructural phase transitions (first-order phase transition FOPT), such as Gd-Si-Ge, La-Fe-Si, Mn-Fe-P-As, and

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