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 CatedráticoProjectos
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).