Synthesis and properties of novel Ba(II)Fe(III) layered double hydroxides

Double hydroxides of Ba(II) and Fe(III) were prepared by the co-precipitation method. Co-precipitation was facilitated by applying highly alkaline, carbonate free NaOH solutions with varying base concentrations (2−20 M). The substances, thus obtained, were characterised by thermal methods, XRD spectra of samples treated at various temperatures, Mössbauer and X-ray absorption spectroscopies. It was found that in extremely concentrated base solutions (≥ 10 M) layered double hydroxides, most probably with intercalated OH− ions, were formed, indeed, while at low base concentration the Fe(III) ions were precipitated as various oxyhydroxides and the Ba(II) ions remained dissolved.