Electron Structure of d-Transition Metals and their Alloys on the Basis of EELS Study

Abstract

Analysis of characteristic electron energy losses in reffection from the surface provides information on electron and band structure of the solid state. Study of transition metals, their alloys (Fe-N, Zn-Ni) and amorphous alloys Fe 78 Si9 B 13 show that there are two subsets of electron gas characterized by different oscillation frequency. The presence of independent components of volume plasmons corresponding to s and d electrons is an evidence that despite collectivization both the subsets preserve individual features characteristic of the structure of an isolated atom. From the energy losses the following quantities are determined: the effective mass (μ) for particular electron subsets, the Fermi energy (EF), the band widths (δE) for s and d electrons and contribution of the subsets to the metal conductivity (γ). The obtained results for metals are compared to analogous data for alloys both in crystalline and amorphous phase.

Quantum confinement in metal nanofilms: Optical spectra

“…As we already noted, we believe that the even-Δn transitions become allowed due to surface irregularities of the film, causing a reduction in the local symmetry and allowing transitions between the adjacent atomic chains. The effective masses are larger than that presently determined in Fe nanofilms, although much smaller than the values calculated for Co and Ni based on EELS studies [ 10]. Note that the effective mass values in the Ni films are slightly different (0.158 vs 0.152), depending on the substrate temperature during deposition.…”

“…Thus, in the 11.3 nm Co film the E F is some 8×10 3 cm -1 above the bottom of the quantum well, while in the 15.1 nm Ni film it is about 9×10 3 cm -1 above the bottom of the quantum well (the last column in Tables 4 and 5). Using the published E F values in bulk transition metals [ 10], we deduce that the bottom of the quantum well is 87×10 3 cm -1 , 54×10 3 cm -1 , and 61×10 3 cm -1 below the vacuum level in Fe, Co and Ni, respectively, for the thickest film studied. Here, we estimate that E F is 14×10 3 cm -1 above the bottom of the quantum well in the 15.6 nm Fe film, using the values of Table 2 for E 1 and n and the expression E n = n 2 E 1 .…”

Structure control of tungsten nanocontacts through pulsed-voltage application

“…where ΔH m,l is the activation energy for diffusion for liquids, k is the Boltzmann's constant, T is the temperature, ΔH f is the latent heat of fusion, and m 0 and m + are the free electron mass and effective mobile electron mass, respectively; ΔH m,l and ΔH f for W are 100 and 54.9 kJ=mol, respectively, 22,23) while m 0 =m + for W was selected to be 1.0 as those of other transition metals (Ti, V, Cr, Zr, Nb, and Mo) are approximately 1.0. 24) We supposed that Eq. ( 1) is applicable to the EM in NCs and estimated the relationship between |Z wd |=Z el and T for liquid W, as shown in Fig.…”

Plasma resonance of binary amorphous and crystalline Al-transition metal alloys: Experiments and ab initio calculations

“…Black dots: our experimental results. Black triangles: published experimental results: pc-Al100−xBex [16,39], pc-Al100−xMgx [15,17,37,39], a-Al100−xCax [20], pc-Al100−xScx [40], pc-Al100−xTix [41][42][43], pc-Al100−xVx [41,42], pc-Al100−xCrx [41,42,44], pc-Al100−xMnx [41,42,45], pc-Al100−xFex [41,42,46], pc-Al100−xCox [41,42,47], pc-Al100−xNix [41,42,48], pc-Al100−xZnx [18,38], pc-Al100−xYx [40,42], pc-Al100−xPdx [49]. In Refs.…”