Evolution of Fe3+ from Framework to Extra-Framework Species in Fe-Silicate as a Function of the Template Burning Temperature S. Bordiga, D. Scarano, C. Lamberti, A. Zecchina, F. Geobaldo, G. Vlaic, R. Buzzoni, G. Tozzola and G. Petrini J. Phys. IV France, 7 C2 (1997) C2-907-C2-908 DOI: 10.1051/jp4:1997275