Effect of high pressure on the Fermi surfaces of zinc and aluminum
The effect of pressures up to 7 kbar on portions of the Fermi surfaces of zinc and aluminum has been determined by using the field-modulation technique to detect de Haasvan Alphen oscillations and by using solid helium as a pressure medium. The primary result obtained in the study of zinc was that the (0001) cross section of the needle portion of the Fermi surface doubled at 3 kbar. This observed behavior is qualitatively in agreement with predictions based on the near1y-free-e1ectron model. A quantitative comparison with this model is complicated/by critical dependence on the cia ratio. The pressure dependence of two Fermi surface cross sections of aluminum was observed. The V-(110] cross section decreased 0.47 Z 0.06% per kbar while the S-[100] cross section increased 1.2 ± 0.15% per kbar. The near1yfree- electron model would predict an increase of 0.074% per kbar for both of these cross sections. The departure of the observed effects from this value is attributed to changes in the band structure of aluminum, which the near1y-freeelectron model does not take into account. A simple model is described which utilizes the pressure dependence of the pseudopotential coefficients to predict changes in the Fermi surface cross sections with pressure. The effects predicted by this model are of the correct order of magnitude and sign to explain the experimental observations.
Fermi surfaces, zinc, aluminum, high pressure, de Haas-van Alphen oscillations
University of Illinois - Urbana-Champaign
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