multifunctional Heusler alloys Ni₄₃Mn_37,8In_12,2Co₇ research with an extraction magnetic calorimeter

 

A. V. Mashirov^1,2, A. P. Kamantsev^1,2, E. T. Dilmieva¹, J. Cwik², V. I. Nizhankovskii²,
I. S. Tereshina^2,3, B. Hernando⁴, L. Gonzalez-Legarreta⁴, V. Vega⁴, V. V. Koledov^1,2,
V. G. Shavrov¹

¹ Kotelnikov Institute of Radio-engineering and Electronics of RAS, Moscow, Russia

² International Laboratory of High Magnetic Fields and Low Temperatures, Wroclaw, Poland

³Baikov Institute of Metallurgy and Materials Science of RAS, Moscow, Russia

⁴ Department of Physics, University of Oviedo, Oviedo, Spain
 

The paper is received on December 1, 2014

 

Abstract. In this paper the multi-functional Heusler alloy Ni₄₃Mn_37,8In_12,2Co₇ is studied in the temperature region near magnetostructural phase transition by the direct method using the extraction calorimeter method in the magnetic fields of the Bitter coil magnet up to 14T. An attractive feature of this alloy is that  the transition from weakly magnetic metamagnetostructural martensite to ferromagnetic austenite takes place at the temperature of 274.9 K. This makes this alloy is very convenient model for studying the inverse MCE. The measurements of the MCE at the initial temperature 274.9 K in an adiabatic and quasiisothermal conditions are done. It was found that the maximum MCE in the adiabatic regime is -2,64K in a magnetic field 6T. The maximum MCE in isothermal mode is 2100 J/kg in a magnetic field 8T. Further increase of the magnetic field to 14T does not improve the MCE.

Key words: magnetocaloric effect, magnetostructural phase transition, Heusler alloys, direct measurement method, extraction magnetic calorimeter, Bitter magnet.