Theory of exchange narrowing in one and two dimensions

Abstract
We show that the theoretical approximations in the Kubo and Tomita theory of electron paramagnetic resonance are such as to make its application to one- and two-dimensional systems dubious. A self-consistent theory based upon the independent-mode approximation, that does not have the defects of the Kubo and Tomita theory, is described, and line shapes are calculated for the strongly narrowed limit. Both theories are in significant disagreement with the experimental results on tetramethyl manganese chloride.