Magnetic and Structural Study of Mn1.15Fe0.85P1-xGex (0.25 < x < 0.32) Magnetocaloric Compounds Prepared by Arc Melting
L. Haweleka, P. Wlodarczyk a, P. Zackiewicz a, M. Polak a, M. Kaminska a, R. Puźniak b, I. Radelytskyi b and A. Kolano-Burian a
aInstitute of Non-Ferrous Metals, J. Sowińskiego 5, 44-100 Gliwice, Poland
bInstitute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warszawa, Poland
Received: May 13, 2015
Full Text PDF
Recently, room temperature magnetocaloric materials increasingly attracted attention in the development of magnetic refrigerators. In this paper, an effect of P/Ge substitution on the magnetic phase transition in the series of Mn1.15Fe0.85P1-xGex (0.25 < x < 0.32) magnetocaloric compounds prepared by the arc melting technique and subsequent homogenization process has been studied. Calorimetric and magnetization results show that the temperature of structural phase transition coincide with the Curie temperature and fall within the temperature range 270-355 K. The magnetic entropy change reaches the maximum value for the compound with x=0.28 and equals to 32 J/(kg K) for the magnetic field change of 5 T. The adiabatic temperature change for the same sample, measured using magnetocalorimeter, is equal to 1.2 K for the magnetic field change of 1.7 T. It was found that the increase of Ge content in the sample causes weakening of first order magnetic transition, which is manifested by the lowering difference in transition temperature measured in two zero-field-cooling and field-cooled-cooling regimes.

DOI: 10.12693/APhysPolA.128.76
PACS numbers: 75.30.Sg, 75.30.Kz, 61.05.C-, 61.66.Fn