An analytical theory of the de Haas-van Alphen effect, under the condition
mu /h omega (c)much greater than1 (where mu is the chemical potential and o
mega (c) the cyclotron frequency) is investigated in two-dimensional and qu
asi-two-dimensional metals, taking into account the effects of spin splitti
ng, impurity scattering, finite temperature, and a field-independent reserv
oir of electrons. The equation for the chemical potential as a function of
magnetic field, temperature, and a non-field-quantized reservoir of states
is derived. It follows that the semiclassical expression in low-dimensional
systems is generally no longer a Fourier-like series. The difficulties in
an unequivocal effective-mass determination from the temperature dependence
of the oscillation amplitude in low-dimensional metals are pointed out. Th
e influence of the chemical potential oscillations on the shape of the magn
etization oscillations is shown analytically: the sawtoothed, inverted sawt
oothed, and symmetrical wave forms are found in high-purity two-dimensional
metals at very low temperatures from a semiclassical expression.