AlPO4-31 derivatives doped with various metals: effects on crystal symmetry and thermal stability

Derivatives of AlPO4-31 have been synthesized with very low contents of Zn, Mg, Mn, Co, Cr, Cu and Cd as dopants. These very low amounts of metals inf luence both the symmetry of the crystal structures (rhombohedral/triclinic symmetry) and the thermal stability of the products. The amount of the intr oduced heterometal plays a more important role than its chemical identity. The results most likely indicate the framework substitution of the metals, though in significantly differing amounts. (C) 1999 Elsevier Science B.V. A ll rights reserved.