De Haas-Van Alphen Effect and Fermi Surface in Palladium

Abstract

PHYSICAL REVIEW LETTERS 1 MARCH 1965 tion temperatures. Our theoretical results should be considered to be preliminary as some of the parameters used in the calculation (such as the effective mass) are not known accurately for SrTiO s . However, both the concentration at which the maximum transition temperature occurs and the transition temperature itself are within the range of uncertainty of the parameters used in the calculations. tWork supported in part by the Advanced Research Projects Agency.Palladium is a particularly interesting transition metal for several reasons. The density of states at the Fermi level, as measured by the electronic specific heat, 1 is the highest for any pure metal, and the magnetic susceptibility is both very large and has an anomalous temperature dependence. 2 ' 3 Attempts to explain this behavior 4 ' 5 have used a model in which the Fermi level lies just above the peak in the density of states in a narrow d band, but there has been little detailed experimental information on the band structure. The galvanomagnetic data 8 indicate that Pd has an open Fermi surface.An experimental determination of the Fermi surface of palladium also provides a test of Mattheiss's prediction 7 that isostructural transition metals have, except for shifts in the Fermi level, very similar band structures. We show that this model accounts for both our data and the galvanomagnetic data.We have observed de Haas-van Alphen oscillations in palladium in the (110) plane and have found that the s band contains 0.36 ±0.01 electron. It is inferred that the d band contains the same number of holes. By postulating a band structure for palladium similar to that for copper 8 and nonmagnetic nickel 9 (all are face-centered cubic), we place the s-band electrons at r and two groups of d-band holes at X. 10 The measurements were made using a modulation technique 11 with modulation frequencies of 600 and 2200 cps and phase-sensitive detection of , Phys. Rev. 135, A1321 (1964). 8 R. A. Cowley, Phys. Rev. 134, A981 (1964).the second harmonic. Data were taken at temperatures between 1.00 and 1.7°K in a 53-kG Varian superconducting magnet. The Pd single crystal had a resistance ratio 4.0xlO 3 . Two distinct sets of periods were observed, one being about 30 times the other. The periods have been converted into extremal crosssectional areas Q 0 of the Fermi surface by using the Onsager 12 relation 4n 2 e 2.673 x 1Q-9 ~ha 0~ a 0where the last form gives the period in reciprocal gauss if a 0 is measured in atomic units. Figure 1 shows these areas as a function of 0, the angle from [100] in the (110) plane. Beats are observed in the fast period around [ill], and these give rise to the double values of the extremal area shown in Fig. 1(a). Clearly these large areas arise from a closed surface which is centered at T because the area is single-valued over most of its range. It can easily be seen that the corresponding Fermi surface has "bumps" in the [ill] directions, and consequently the smaller area at [ill] is the central secti...

De Haas-van Alphen Effect and Fermi Surface in Palladium

“…The results discussed in the previous section are interpreted as in the preliminary report 13 in terms of a rigid-band model. This is justified by its success in accounting for the observed Fermi surface of Pd; there are no complete and independent Pd band structure calculations, although the d bands have been treated by Friedel et al 21 The Ag band structure is the evident choice for a comparison, but the relative positions of the s and d bands in the Ag calculations 22 Fig.…”

“…It should be noted that the field measurements used in a preliminary publication 13 were uniformly 1% high because of an error in the location of the current resistor.…”

“…The first observation of the dHvA effect in Pd was made by the pulsed-field technique. 12 Preliminary results 13 with the field-modulation technique (discussed in Sec. II) showed that the Fermi surface of Pd was consistent with a band structure like that of Cu, with the Pd Fermi level displaced to just below the top of the d bands.…”

Correlation between hydrogen storage properties and amount of alloy particles in Mg-based composites

“…The hydrogen absorption depends both on lattice volume and electronic effects between hydrogen and metals in the alloy. In addition, there will be charge transfer from hydrogen to metal or vice versa [16][17][18][19]. However, it is assumed that the hydrogen interstitials results in the volume expansion in similar alloys and therefore in the present work the lattice volume effect is discussed.…”

Influence of hydrogen on electron transport of palladium alloyed with silver

“…The experimental results (see e.g., [1]) indicated that both, silver and hydrogen introduced into a palladium matrix acted as electron donors. More subtle experiments (de Haas-van Alphen effect [2]) and theoretical calculations (see e.g., [3] and [4]) indicated that the electronic structure was more complex than that resulting from the rigid band model. Nevertheless, the main assumption of the latter that additions of silver or hydrogen shift the Fermi level towards higher energies and the empty 4d states are filled up if the number of valence electrons exceeds ca.…”