Electronic magnetostriction of Bi1-xSbxalloys

The magnetostriction of Bi 1-x Sb x narrow-gap semimetals and semiconductors has been measured at 4.2K as a function of magnetic field for values of x<10 at.%. The field-induced strain is due to the change in the free carrier densities and energies, in turn due to the Landau level quantisation: the crystal size changes to minimise the sum of the elastic and electronic free energies. A quantitative model, involving a compilation of the literature on the band structure of these alloys, is developed and compared with the authors' data.