ON THE CORRELATED INCORPORATION OF CU(II) SPECIES IN ALPHA-ALF3-CENTER-DOT-3H(2)O AND BETA-ALF3-CENTER-DOT-3H(2)O - AN ESR STUDY OF THERMAL-BEHAVIOR

A one-for-one substitution of Al3+ ions by Cu2+ ions in solids remains unknown thus far. Therefore, an incorporation of Cu2+ ions into alpha -AlF3 . 3H(2)O and beta-AlF3 . 3H(2)O was attempted. ESR spectroscopic in situ investigations (X band) were carried out in the temperature r ange of 2 K less than or equal to T less than or equal to 1073 K. The comparison of experimental with simulated ESR coupling tensors showed that both compounds allowed the incorporation of Cu2+ ions in a correl ated manner. Depending on the reaction temperature, dimeric and monome ric species could be detected which provide the necessary compensation of charge and geometrical misfit. During thermal treatment, a superim position of thermal and chemical processes takes place, assisted by th e transition metal ions present. (C) 1995 Academic Press, Inc.