Investigation on the magnetic stability of MnFePX(X=Si,Ge,As) alloys for magnetocaloric application by first principles calculations
| Title: |
Investigation on the magnetic stability of MnFePX(X=Si,Ge,As) alloys for magnetocaloric application by first principles calculations |
| DNr: |
SNIC 2015/1-99 |
| Project Type: |
SNIC Medium Compute |
| Principal Investigator: |
Börje Johansson <borje.johansson@fysik.uu.se> |
| Affiliation: |
Kungliga Tekniska högskolan |
| Duration: |
2015-05-01 – 2016-05-01 |
| Classification: |
10304 20502 |
| Keywords: |
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Abstract
Recently, magnetic refrigeration techniques based on the magnetocaloric effect have been considered as a promising alternative to conventional vapor-cycle refrigeration used today. Since the discovery of large magnetocaloric effect in hexagonal Fe2P-type FeMnPAs compounds, this family of compounds attracts much attention as promising magnetocaloric candidate materials. Recently, great achievements have been made in FeMnPX (X=Si, Ge, As) alloys. Experimentally, good magnetocaloric properties, tunable Curie temperature and magnetic transition temperature hysteresis and rich magnetic phenomena have been observed in FeMnPX (X=Si, Ge, As) alloys. This makes this system in intense focus from the point views of both fundamental science and technology application due to their remarkable potential as magnetocaloric candidate materials.
In order to explore stable magnetostructural coupling in hexagonal ferromagnets for magnetocaloric application in future, in this project, we will investigate the magnetic relative stability of hexagonal FeMnPX (X=Si, Ge,As) alloys by the first principles calculations in 2×2×2 supercell (36 atoms). By optimizing the ratios of Fe/Mn and P/X atoms, the total energy and magnetic exchange interaction for the samples with different atomic disorder occupation level and structural parameter will be investigated. By considering the stability of high temperature paramagnetic state, we will also explore the origin of wide temperature hysteresis during the magnetic transition, the thermal-history dependent origin effect and magnetic properties. Our study will be helpful to understand the nature of magnetic stability as well as to explore high efficiency and stable magneto-caloric compounds. These investigations about FeMnPX (X=Si, Ge, As) compounds will provide more options for developing new magnetocaloric materials.
