Effect of Carbon Doping on the Structure and Magnetic Phase Transition in (Mn,Fe<sub>2</sub>(P,Si))

Journal article (2017)

Authors

V.T. Nguyên RST/Fundamental Aspects of Materials and Energy - AS
. Yibole RST/Fundamental Aspects of Materials and Energy - AS
X.F. Miao RST/Fundamental Aspects of Materials and Energy - AS
K. Goubitz RST/Fundamental Aspects of Materials and Energy - AS
L. van Eijck RST/Neutron and Positron Methods in Materials - AS
N.H. van Dijk RST/Fundamental Aspects of Materials and Energy - AS
E.H. Brück RST/Fundamental Aspects of Materials and Energy - AS
Research Group
RST/Fundamental Aspects of Materials and Energy (AS) (TU Delft)
Copyright: © 2017 V.T. Nguyên, . Yibole, X.F. Miao, K. Goubitz, L. van Eijck, N.H. van Dijk, E.H. Brück
DOI: https://doi.org/10.1007/s11837-017-2400-0
More Info
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Published Date

01-08-2017

Language

English

Faculty

Applied Sciences

Department

RST/Radiation, Science and Technology

Research Group

RST/Fundamental Aspects of Materials and Energy

Abstract

Given the potential applications of (Mn,Fe2(P,Si))-based materials for room-temperature magnetic refrigeration, several research groups have carried out fundamental studies aimed at understanding the role of the magneto-elastic coupling in the first-order magnetic transition and further optimizing this system. Inspired by the beneficial effect of the addition of boron on the magnetocaloric effect of (Mn,Fe2(P,Si))-based materials, we have investigated the effect of carbon (C) addition on the structural properties and the magnetic phase transition of Mn 1.25Fe 0.70P 0.50Si 0.50C z and Mn 1.25Fe 0.70P 0.55Si 0.45C z compounds by x-ray diffraction, neutron diffraction and magnetic measurements in order to find an additional control parameter to further optimize the performance of these materials. All samples crystallize in the hexagonal Fe 2P -type structure (space group P-62m), suggesting that C doping does not affect the phase formation. It is found that the Curie temperature increases, while the thermal hysteresis and the isothermal magnetic entropy change decrease by adding carbon. Room-temperature neutron diffraction experiments on Mn 1.25Fe 0.70P 0.55Si 0.45C z compounds reveal that the added C substitutes P/Si on the 2c site and/or occupies the 6k interstitial site of the hexagonal Fe 2P -type structure.