Distribution of nuclear quadrupole splittings ofFe57in amorphous ferric fluorides: Structural implications

Experimental results for the distribution $P\left(\Delta \right)$ of the nuclear quadrupole splitting of ${}_{}{}^{57}{}_{}{}^{}\mathrm{Fe}$ in amorphous ferric fluorides, reported by two independent groups, are discussed. For the materials studied, $P\left(\Delta \right)$ is approximately proportional to $\Delta$ for small $\Delta$. It is shown that this result in conjunction with the isomer shift values reported indicates that the ${\mathrm{Fe}}^{3+}$ ions in these materials are surrounded by randomly distorted ${\left({\mathrm{F}}^{-}\right)}_6$ octahedra and that the distortions are described by two independent random variables.