Key points are not available for this paper at this time.
This note discusses briefly several methods of describing the width and shape of the resonances characteristic of nuclear paramagnetism. Use of the so-called moments of the shape function is illustrated by an experimental determination of a root mean square line width which is in substantial agreement with a calculation by Van Vleck. The solutions of the Bloch equations, which lead to the Lorentz shape function traditional in the theory of radiation- and collision-broadened lines, are compared with susceptibility curves based on a Gauss absorption curve. A significant difference between the two dispersion curves serves as a criterion for determining whether or not either of these two shapes closely approximates to a given experimental curve, and experimental examples of each are given.For comparison of shape functions, several well-known specializations of the Kronig-Kramers relations are employed. The collection of these formulae may incidentally prove convenient and useful to those engaged in studies of nuclear paramagnetism.
Pake et al. (1948) studied this question.