Spin-orbit coupling constants of transition metal atoms and ions in density functional theory

W-capped Co nanoparticles dispersed in an alumina matrix are studied by means of high-resolution transmission electron microscopy, extended x-ray absorption fine structure, SQUID-based magnetic measurements, dc magnetization, ac magnetic susceptibility, and x-ray magnetic circular dichroism. Results show the formation of amorphous Co-W alloy nanoparticles, the magnetic properties of which are modified by the amount of W or Co present in the samples. The average Co magnetic moment depends on the number of W atoms surrounding it. Co-W particles show superparamagnetic behavior and are described as an array of noninteracting particles with random anisotropy axes and an average moment per particle proportional to the particle volume and to the average Co moment for each alloy composition. Values of the magnetic anisotropy constant of the particles are on the order of 10 6 erg/cm 3 , higher than that of bulk Co. Evidence of short-range ordering within each amorphous particle is found that provides insight of the origin of their magnetic anisotropy.

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“…72) and W (Ref. 73), respectively]. However, the enhancement driven by surface effects observed in the bare pure Co NPs is significantly larger.…”

Section: Discussionmentioning

confidence: 96%

Structural and magnetic properties of amorphous Co-W alloyed nanoparticles

et al. 2011

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“…15 This behavior is easily understood if one takes into account that the amount of zfs into triplet sublevels is strongly dependent on spin-orbit coupling (soc) and that the soc constant is about two orders of magnitude larger for the 4d-orbitals of Ru 2 § than for the ~r* orbitals of the ligands (cf. [136,254,255] to [256,257]). Effects resulting from these properties have already been studied on the basis of experimental data.…”

Section: Localized Situation In [Ru(i-biq)2(bpy)2] 2 §mentioning

confidence: 99%

“…11). However, compared to [Ru(bpy)3] 2+, the sequence of the resulting electronic states and their individual properties may be quite different, due to the much larger spin-orbit coupling (soc) in Os(II)-complexes (soc constant 2[Os(II)]: = 3 9 103 cm-~; 2[Ru(II): = 103 cm -1, see [123,136,153,254,255]). Moreover, the d-d states of the third-row transition Gonsequently, we want to use an experimental approach to characterize these states by applying the information displayed in highly resolved emission and absorption or excitation spectra.…”

Section: [Os(bpy)~] Z+mentioning

confidence: 99%

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Characterization of excited electronic and vibronic states of platinum metal compounds with chelate ligands by highly frequency-resolved and time-resolved spectra

Yersin

Humbs

Strasser

1997

Topics in Current Chemistry

133

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The lowest excited electronic states of triplet character and related vibronic properties are discussed in detail on the basis of highly frequency-resolved and time-resolved emission and excitation spectra of per-protonated, per-deuterated, and partially deuterated [Pt(bpy)2] 2+, [Rh(bpy)3] 3+, [Ru(bpy)3] 2+, and [Os(bpy)3] ~+. Emphasis is placed on the use of the enormous amount of information displayed in well-resolved vibrational satellite structures. For comparison, IR data and Raman spectra are also used. In addition, data are given for [Ru(bpz)Pt(3-thpy) 2, Pt(2-thpy)(CO)(Cl), Pt(2-thpy) 2, Pt(qol)2, Pt(qtl)2. Trends and effects are also addressed, which are related to the amount of metal d-orbital mixing. In particular, we discuss the role of traps and sites in the context of high-resolution, site-selective, and line-narrowed spectra of chromophores doped into matrices; the interplay between states of ligand-centered 3rtrr* and ~MLCT character; localization versus delocalization behavior; radiative decay properties; zero-field splittings; spin-lattice relaxations via direct and Orbach mechanisms; Arrhenius behavior after time delay; Franck-Condon activities and Huang-Rhys factors; Franck-Condon versus Herzberg Teller activities and tunability of these activities under high magnetic fields; isotope marking and deuteration effects; aggregate formation of [Ru(bpy)3]2+; and radiationless energy transfer in neat [Ru(bpy)3](PF6) 2. These effects are in part treated in detail, but the aim is to use easy-to-follow descriptions. In particular, it is emphasized throughout this review that chemical tunability opens fascinating possibilities for controlled variation of physical properties.

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“…To estimate key parameters in the model of Fert and Levy, we take from experiment the values for λ d of 0.032 eV for Cr and 0.38 eV for W [24]. From the shape of the ab-initio DOS, Fig.…”

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confidence: 99%

Giant spin Nernst effect induced by resonant scattering at surfaces of metallic films

et al. 2016

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A new concept realizing giant spin Nernst effect in nonmagnetic metallic films is introduced. It is based on the idea of engineering an asymmetric energy dependence of the longitudinal and transverse electrical conductivities, as well as a pronounced energy dependence of the spin Hall angle in the vicinity of the Fermi level by the resonant impurity states at the Fermi level. We employ an analytical model and demonstrate the emergence of a giant spin Nernst effect in Ag(111) films using ab-inito calculations combined with the Boltzmann approach for transport properties arising from skew scattering off impurities. PACS numbers: 72.25.Rb, 73.50.Bk, 72.25.Ba, Within the past few years, the field of spin caloric transport has attracted broad interest owing to new challenges and vistas in applications which combine spintronic as well as thermoelectric concepts [1]. In this field, thermal gradient is used as an ultimate agent to generate a spin current, in analogy to the generation of a charge current in conventional thermoelectrics. As a promiment spincaloritronics phenomenon, the relativistic spin Nernst effect (SNE) enables a way to generate a pure transverse spin current in a sample subject to an applied temperature gradient [2][3][4]. The SNE bears an analogy to the spin Hall effect (SHE) [5,6], which has become one of the most efficient ways of generating spin currents in spintronics. Owing to the fact that the SHE has been successfully observed in various types of experiments [7][8][9], it is expected that the spin Nernst effect would also be detectable. However, limitations on the magnitude of temperature gradients in metals can diminish the magnitude of the spin Nernst currents [10].Ab-initio studies [11][12][13][14] and experiments [15] suggest that the extrinsic SHE induced by the skew-scattering off impurities can be large due to a large difference in the spin-orbit coupling strength of the impurities and the host. However, this argument is not applicable to the SNE, because the thermal transport coefficients entering the expression for the spin Nernst conductivity (SNC) are determined to a first approximation by the derivative of the conductivities around the Fermi energy (E F ), and not by the their values directly at it. As a consequence, the SNE is more sensitive to changes in the electronic structure as a function of energy, as compared to the SHE. A requirement for the SNC to be large is that the energy dependence of the conductivities should be very asymmetric with respect to E F .Recently, Tauber et al. [10,16], using first-principles techniques combined with Boltzmann approach, computed the SNE in Cu bulk, caused by spin-dependent scattering off substitutional impurities such as Ti, Au, Bi. The magnitude of the SNC was predicted to be about 16 (A/K m) at 300 K in Cu 0.99 Au 0.01 alloy. It corresponds to a spin current of about 10 µA when using a sample with the dimensions of 100×100×100 nm [9] and a temperature gradient of 50 K/µm [17]. For the same Cu(Au) alloy, Wimmer et al. obtained a somewhat ...

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Spin-orbit coupling constants of transition metal atoms and ions in density functional theory

Cited by 61 publications

References 11 publications

Structural and magnetic properties of amorphous Co-W alloyed nanoparticles

Structural and magnetic properties of amorphous Co-W alloyed nanoparticles

Characterization of excited electronic and vibronic states of platinum metal compounds with chelate ligands by highly frequency-resolved and time-resolved spectra

Giant spin Nernst effect induced by resonant scattering at surfaces of metallic films

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