ESR EVIDENCE OF ORDER DISORDER TRANSITIONS IN SOLIDS CAUSED BY DEHYDRATION/

ESR spectroscopy was used to study order/disorder phenomena in paramag netically doped solids. The dehydration process of aluminium fluoride and oxide hydrates and aluminosilicates was examined by ESR in situ me asurements as well as using thermoanalytically quenched samples. Two t ypes of amorphous states of solids have been studied: inorganic glasse s in the conventional sense and amorphous states of solids which have not passed the liquid state. The complete ESR fine structure pattern o f Fe3+ ions is susceptible with respect to order/disorder processes of the actual host matrix. Dehydration processes bear some model charact er in this field. A quantitative description of the disorder effects o n the Fe3+ ESR could be given on the basis of a complete spin Hamilton ian using distributions of the fourth order spin coupling parameters.