Yttrium β‐Diketonate Glyme MOCVD Precursors: Effects of the Polyether Length on Stabilities, Mass Transport Properties and Coordination Spheres

Abstract

AbstractThe glyme adducts of trishexafluoroacetylacetonato yttrium, [Y(hfa)3·monoglyme], [Y(hfa)3·diglyme], [Y(hfa)3·(H2O)2·triglyme] and [Y(hfa)2·tetraglyme]+[Y(hfa)4]− {CH3(OCH2CH2)nOCH3, n = 1 monoglyme, 2 diglyme, 3 triglyme and 4 tetraglyme}, were synthesized and characterized by elemental analysis, mass spectrometry, and IR, 1H and 13C NMR spectroscopy. Additionally, [Y(hfa)3·monoglyme] and [Y(hfa)3·diglyme] were characterized by single‐crystal X‐ray diffraction studies. The mass‐transport properties of these adducts were investigated by thermogravimetric analysis, differential scanning calorimetry, evaporation‐rate measurements and chemical vapour‐deposition experiments. There is evidence of high volatility and very good thermal stabilities with a residue lower than 2−4 %. Vaporization‐rate experiments proved that all adducts are well‐suited for metal‐organic chemical vapour‐deposition experiments. The [Y(hfa)3·monoglyme] complex was successfully applied in the low‐pressure MOCVD process of YBaCuO HTc superconductor using a multimetal molten single source. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)