De Haas van Alphen Effect in Zinc Manganese Alloys

Abstract

Observations of the long period de Haas van Alphen effect in pure zinc and in a zinc alloy containing 0.01 at.% manganese have been made to determine whether the Fermi surface of the alloy changes in the temperature region where the zinc manganese alloy exhibits an electrical resistance minimum. On the basis of a nearly free electron interpretation it has been shown that: (i) Within the experimental error the Fermi surface of pure zinc and the 0.01 at.% zinc manganese alloy are identical. (ii) The number of electrons added or subtracted from the conduction band on alloying cannot be greater than 1 electron per impurity atom. (iii) If the resistance minimum is due to a change in the density of states in the conduction band, this change is less than 0.0015%. (iv) If the ionic state of the manganese ions changes in the temperature range of the resistance minimum, then less than half of the ions are involved. In order to obtain a consistent interpretation of the variation of the amplitude of the de Haas van Alphen oscillations in the alloy it was necessary to assume that the collision damping (Dingle) factor varies with magnetic field. A simple extension of the Schmitt scattering model [R. W. Schmitt, Phys. Rev. 103, 83 (1956)] would predict this behavior both for the relaxation time derived from magnetoresistance and the de Haas van Alphen effect.