Hydrogen insertion, ESR and Mossbauer studies of CU0.5TaFeP3O12

A new copper Nasicon of composition Cu0.5TaFeP3O12 has been prepared and reduced under hydrogen flow at 500 and 675 degrees C, separately. The unreduced and reduced products are characterized by IR spectra and powder X-ray diffraction. The copper Nasicon and the products obtained by its reduction crystallize in the rhombohedral lattice with space group R (3) over barc. The ESR and Mossbauer spectral results suggest only partial reduction of both Cu2+ and Fe3+ to Cu+ and Fe2+, respectively, with simultaneous hydrogen insertion to balance the charge. A reaction in conformity with the obtained results is proposed. (C) 2005 Elsevier Ltd. All rights reserved.