The orientation of the electric-field-gradient tensor from single-crystal Mössbauer measurements

Abstract

The problem of determining the orientation of the electric-field-gradient tensor from Mossbauer single-crystal data is discussed generally in terms of the point symmetries of the resonant site and the space group. The effects of finite thickness, polarization, and anisotropy in the recoilless fraction are all taken into account. In many important cases it is possible to determine the relevant parameters from only one crystal by using a combination of polarized and unpolarized radiation, and several examples are discussed in detail.