Structural study of the metamict states by X-ray diffraction: In the case of naegite

Abstract

A structural study of the metamict zircon “naegite” has been carried out by obtaining radial distribution function (RDF) from measured X-ray scattering intensity data. Structural parameters of interatomic distances and coordination numbers were estimated from the RDF data using the pair function method. The silicon atom was found to occupy a tetrahedral site of oxygen. The structural parameters of first neighbouring Zr–O pair agree well with those of crystalline zircon, although the slight decrease in its interatomic distance is detected. Since the correlation of the cation-cation pairs around 0.30 and 0.36nm are well attributed to those of the crystalline zircon, the metamict zircon is considered to have similar short range order as that found in the structure of crystalline zircon.