Artículos de revistas
Conduction Electrons Mediating The Evolution From Antiferromagnetic To Ferromagnetic Ordering In Gd(co1-yfey)(2)zn-20 (0 <= Y <= 1)
Registro en:
Physical Review B. Amer Physical Soc, v. 95, p. , 2017.
2469-9950
2469-9969
WOS:000396001800006
10.1103/PhysRevB.95.104407
Autor
Cabrera-Baez
M.; Naranjo-Uribe
A.; Osorio-Guillen
J. M.; Rettori
C.; Avila
M. A.
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) GdFe2Zn20 is a complex cagelike compound with an unusually high ferromagnetic ordering temperature (T-C = 86 K) for a very diluted Gd3+ magnetic sublattice, embedded in a matrix that features strong electronelectron correlations. Here, we report on a magnetic and electronic study of the substitutional intermetallic system Gd(Co1-y Fe-y)(2)Zn-20 combining magnetizationmeasurements plus first-principles density functional theory (DFT) calculations with temperature-dependent electron spin resonance (ESR). After accounting for electron-electron correlations and itinerant molecular field effects, the ESR results indicate that the exchange interaction between the Gd3+ is processed via a single band of d-type electrons at the Fermi level and the exchange interaction is covalent in nature [J(0)(fd) < 0] with a strong conduction electron (ce) momentum transfer dependence [Jfd (q)]. The DFT calculations support this scenario by indicating a major contribution of d-type ce at the Fermi level and a spin polarization in (Y, Gd) Fe2Zn20 wherein the most stable configuration is antiferromagnetic between Gd3+ and ce spins. Our results demonstrate that the standard Ruderman-Kittel-Kasuya-Yosida mechanism cannot explain the ferromagnetic behavior of GdFe2Zn20 and a superexchangelike mechanism is proposed for this magnetic interaction. An "extended phase diagram" for the double substitution sequence YCo2Zn20. GdCo2Zn20. GdFe2Zn20 is presented and discussed. 95 10 Brazilian agencies FAPESP [2011/19924-2, 2012/17562-9] CNPq FINEP CAPES Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)