resumo
Heusler alloys are promising for several applications, including magnetic refrigeration, due to high magnetocaloric and magnetovolume effects. One way to optimize this potential is by increasing the magnetovolume effect. Using density functional theory with the Korringa-Kohn-Rostoker method, we calculate the effective exchange interaction energies and corresponding mean field Curie temperature as a function of the volume (hydrostatic pressure) in several L2(1)-type Co(2)YZ Heusler alloys. Different qualitative trends and signs of the pressure derivatives of the Curie temperature and moments are found among these compounds, discussed and compared with previous calculations and experiments.
palavras-chave
EXCHANGE INTERACTIONS; CURIE-TEMPERATURE; ALLOYS; DISORDER; SN
categoria
Engineering; Physics
autores
Goncalves, JN; Amaral, JS; Amaral, VS
nossos autores
João Cunha de Sequeira Amaral
Investigador Auxiliar
João Nuno Santos Gonçalves
Investigador
Vitor Brás Sequeira Amaral
Professor CatedráticoProjectos
Micro and nanostructures with giant magnetostriction: production, optimization and application in multifunctional devices (Strictive4Device) (PTDC/CTM-NAN/115125/2009)
Exploring nano-fabrication methods of high coercivity rare-earth free Si-Alnico permanent magnets (EXPL/CTM-NAN/1614/2013)
Centre for Research in Ceramics and Composite Materials - CICECO (LA0011: 2013-2014) (PEst-C/CTM/LA0011/2013)
agradecimentos
The work of J. N. Goncalves and J. S. Amaral was supported in part by the Fundacao para a Ciencia e a Tecnologia under Grant SFRH/BPD/82059/2011 and Grant SFRH/BPD/63942/2009. This work was supported in part by FEDER COMPETE, in part by the Research Project PTDC/CTM-NAN/115125/2009, in part by the EXPL/CTM-NAN/1614/2013 Project under Grant FCOMP-01-0124-FEDER-041688, and in part by the PEst-C/CTM/LA0011/2013 Project under Grant FCOMP-01-0124-FEDER-037271.