resumo
The magnetic properties tuning and volume dependence in the series of quaternary full Heusler alloys with formula Co2Cr1-xYxGa (Y= Ti, V, Mn, Fe, Co, Ni) were studied with a detailed first-principles exploration. We employ the density functional KKR method with the coherent potential approximation, estimating effective Heisenberg exchange constants via the magnetic force theorem together with mean-field Curie temperature (T-C) and magnetic moment for compositions in the whole concentration range. The volumetric dependency of these magnetic properties is studied, particularly the pressure derivatives of T-C at equilibrium. Our ternary alloy calculations show good agreement with local-density and generalized gradient approximations in the literature. The quaternary alloys show a wide range of tunable magnetic properties, where magnetic moments range from 0.8 to 4.9 mu B, T-C from 130 K to 1250 K, and dTC/dV values range from -7 to + 6.3 K angstrom(-3).
palavras-chave
CURIE-TEMPERATURE; EXCHANGE INTERACTIONS; HYDROSTATIC-PRESSURE; NI2MNSN; METALS
categoria
Materials Science; Physics
autores
Goncalves, JN; Fortunato, NM; Amaral, JS; Amaral, VS
nossos autores
João Cunha de Sequeira Amaral
Investigador Auxiliar
João Nuno Santos Gonçalves
Investigador Júnior
Nuno Fortunato
Bolseiro de investigação
Vitor Brás Sequeira Amaral
Professor CatedráticoGrupos
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G6 - Materiais Virtuais e Inteligência Artificial
Projectos
agradecimentos
This work was supported by the project RECI/CTM-CER/0336/2012 co-financed by FEDER, QREN reference COMPETE: FCOMP-01-0124-FEDER-027465 and was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and co-financed by FEDER under the PT2020 Partnership Agreement. We acknowledge FCT grants SFRH/BPD/111270/2015 (J. S. Amaral) and SFRH/BPD/82059/2011 (J. N. Goncalves).