Electronic structure and spin-filter effect of ferromagnetic insulators with double perovskite structure

Itoh, H.; Ozeki, J.; Inoue, Jun–ichiro

doi:10.1016/j.jmmm.2006.10.688

Cited by 15 publications

(5 citation statements)

References 20 publications

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“…2 A way of obtaining a highly spin polarized current is by using a spin filtering effect through ferromagnetic-insulator-ferromagnetic tunnel barriers. 3,4 The same effect can be obtained simply by using a ferromagnetic insulating barrier. 5,6 However, ferromagnetic insulators (FMI) are very scarce; among the few FMI known double perovskite (DP) oxides, like La 2 NiMnO 6 (LNMO) and La 2 CoMnO 6 , have attracted considerable attention due to their high Curie temperature, T C , and magnetodielectric properties.…”

Section: ■ Introductionmentioning

confidence: 71%

“…The development of spintronic devices requires the generation and control of highly spin-polarized currents or pure spin currents . A way of obtaining a highly spin polarized current is by using a spin filtering effect through ferromagnetic-insulator-ferromagnetic tunnel barriers. , The same effect can be obtained simply by using a ferromagnetic insulating barrier. , However, ferromagnetic insulators (FMI) are very scarce; among the few FMI known double perovskite (DP) oxides, like La 2 NiMnO 6 (LNMO) and La 2 CoMnO 6 , have attracted considerable attention due to their high Curie temperature, T C , and magnetodielectric properties. − In both cases, the ferromagnetic (FM) ordering is explained by superexchange interaction between Mn 4+ and Ni 2+ or Co 2+ according to the Goodenough-Kanamori rules, and it is very sensitive to the ordered distribution of cations in the B-sublattice of the DP structure . In the case of LNMO, cationic order gives rise to 180° ferromagnetic interactions between Ni 2+ (d 8 , t 2g 6 e g 2 , S = 1) and Mn 4+ (d 3 , t 2g 3 e g 0 , S = 3/2) ions and results in a T C very close to RT ( T C ≈ 280 K).…”

Section: Introductionmentioning

confidence: 99%

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Nonstoichiometry Driven Ferromagnetism in Double Perovskite La₂Ni_1–xMn_1+xO₆ Insulating Thin Films

Bernal-Salamanca

Konstantinović

Balcells

et al. 2019

Crystal Growth & Design

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In this work we report on the epitaxial growth of La 2 NiMnO 6 double perovskite thin films on top of (001) oriented SrTiO 3 substrates by RF magnetron sputtering. The influence of oxygen pressure (P O 2 ) and growth temperature on the microstructure, stoichiometry of the films, and magnetic and transport properties is thoroughly investigated. It is found that high oxygen pressure promotes the growth of stoichiometric films, with a Ni/Mn ratio almost equal to 1. However, these films exhibit poor ferromagnetic properties with respect to the expected optimum values corresponding to ferromagnetic ordering mediated by superexchange interaction between Mn 4+ and Ni 2+ according to the Goodenough-Kanamori rules. Most interestingly, films grown at low P O 2 exhibit Ni/Mn ratios below 1, but ferromagnetic properties close to the optimal ones. The valence balance between Ni and Mn ions in nonstoichiometric sample has been elucidated by X-ray absorption spectroscopy. The results indicate that Ni deficiency plays a crucial role in the puzzling insulating ferromagnetic behavior observed in nonstoichiometric samples.

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Section: ■ Introductionmentioning

confidence: 71%

Section: Introductionmentioning

confidence: 99%

Nonstoichiometry Driven Ferromagnetism in Double Perovskite La₂Ni_1–xMn_1+xO₆ Insulating Thin Films

Bernal-Salamanca

Konstantinović

Balcells

et al. 2019

Crystal Growth & Design

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“…Here, the Fermi level is taken as the origin of the energy scale. Details of the fitting will be given separately [39]. The tunnel conductance is calculated in the ballistic limit under an assumption that the Fermi level locates at the middle of the band gap.…”

Section: Spin Filter Effectmentioning

confidence: 99%

Theory of tunnel magnetoresistance and spin filter effect in magnetic tunnel junctions

Itoh¹

2007

J. Phys. D: Appl. Phys.

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Tunnel magnetoresistance (TMR) and spin filter effect in magnetic tunnel junctions are studied by using numerical simulations based on the linear response theory. In Fe/MgO/Fe junction, TMR is calculated for both clean and disordered systems. Large MR ratio obtained in clean junctions is attributed to the momentum and symmetry filter effect of MgO barrier. It is shown that lattice distortions within MgO and at the interfaces decrease the MR ratio because the disorder weakens the filter effects and causes hybridization between Bloch wave functions having different momenta and symmetries. The spin filter effect in junctions containing a ferromagnetic insulator LaNi0.5Mn0.5O3 is also investigated. It is shown that a large spin filter effect is obtained in LaNiO3/LaNi0.5Mn0.5O3/LaNiO3 junctions although the tunnel barrier height is spin independent.

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“…The presence of electro-magnetic coupling makes these compounds compatible with modern electronic devices. In these compounds, the presence of small conductivity, near and above room temperature, offered a new class of dielectric materials, known as leaky dielectric materials, used for microelectronic applications [1][2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Structural, Electrical and Magnetic Study in Nanocrystallite La2CuMnO6 Ceramics

Singh

Majumder

Mishra

et al. 2021

Preprint

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Structural, dielectric and magnetic properties of nano-size polycrystalline, La2CuMnO6 (LCM) samples were studied in the temperature range 80 K to 300 K. Orthorhombic single phase with space group 'Pnma' was confirmed by Rietveld refinement of XRD peaks. The small-polaron driven dielectric dispersion showed relaxation peaks in the vicinity of low-temperatures. The X-ray absorption spectroscopy (XAS) confirmed the charge states of Cu (2+) and Mn (4+) ions. DC-resistivity analysis supported the thermally activated conduction for high temperature and the variable range hoping (VRH) mechanism of conduction at low-temperature. The deviation of super-exchange angles between B-site cations from an ideal 180º value produced non-collinearity in the antiferromagnetic response of this ceramic and was confirmed canted antiferromagnetic behaviour. Positive Curie temperature along with finite coercivity indicated that the super-exchange interaction between Cu2+ and Mn4+ ions influenced the magnetic behaviour of this ceramics and showed a heterogenous magnetic response.

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Electronic structure and spin-filter effect of ferromagnetic insulators with double perovskite structure

Cited by 15 publications

References 20 publications

Nonstoichiometry Driven Ferromagnetism in Double Perovskite La₂Ni_1–xMn_1+xO₆ Insulating Thin Films

Nonstoichiometry Driven Ferromagnetism in Double Perovskite La₂Ni_1–xMn_1+xO₆ Insulating Thin Films

Theory of tunnel magnetoresistance and spin filter effect in magnetic tunnel junctions

Structural, Electrical and Magnetic Study in Nanocrystallite La2CuMnO6 Ceramics

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Electronic structure and spin-filter effect of ferromagnetic insulators with double perovskite structure

Cited by 15 publications

References 20 publications

Nonstoichiometry Driven Ferromagnetism in Double Perovskite La2Ni1–xMn1+xO6 Insulating Thin Films

Nonstoichiometry Driven Ferromagnetism in Double Perovskite La2Ni1–xMn1+xO6 Insulating Thin Films

Theory of tunnel magnetoresistance and spin filter effect in magnetic tunnel junctions

Structural, Electrical and Magnetic Study in Nanocrystallite La2CuMnO6 Ceramics

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Product

Resources

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Nonstoichiometry Driven Ferromagnetism in Double Perovskite La₂Ni_1–xMn_1+xO₆ Insulating Thin Films

Nonstoichiometry Driven Ferromagnetism in Double Perovskite La₂Ni_1–xMn_1+xO₆ Insulating Thin Films