Indirect exchange in semiconductors

Indirect exchange of the Ruderman-Kittel type is discussed for donor and conduction electrons in a semiconductor. It is found that the indirect exchange no longer shows the spatial oscillations characteristic of a metal, and is increased in magnitude, though limited spatially to the size of the wavefunction, when the electrons are localized on nonoverlapping donors. The indirect exchange is much too small in magnitude to lead to ferromagnetism in either extrinsic or intrinsic semi-conductors. © 1966.