de Haas—van Alphen Effect in Antimony-Tin Alloys

The de Haas---van Alphen (dHvA) effect was used to measure the Fermi surfaces of pure antimony and antimony alloys with up to 0.29-at.% tin. At the highest concentration, the hole dHvA frequencies increased by 75% and the electron frequencies decreased to less than half of the pure-antimony values. Cyclotron masses of electrons and holes at absolute frequency minima increased and decreased for holes and electrons, respectively, giving a definite indication of nonparabolic conduction and valence bands. A comparison of the hole- and electron-Fermi-surface volumes with the number of tin atoms added showed that one tin atom removes one electron from the alloy as expected from the unit valence difference between antimony and tin. This result corrects that found by other workers using different techniques. Extrapolation of the hole and electron densities in the alloys indicates that the electron pocket will be empty at {~} 0.35-at.% tin while the hole pocket will disappear at about the same concentration of a hexavalent element such as tellurium. The rigid-band predictions without any corrections for changes of lattice parameter describe the observed frequency shifts quite well at low concentrations. At higher values there is a deviation caused by the mass and Fermi-surface-shape changes. The Fermi-surface shape and cyclotron mass are also discussed in terms of a band structure determined from the Falicov---Lin pseudopotential.