Synthesis, Characterization, and Mass-Transport Properties of Two Novel Gadolinium(III) Hexafluoroacetylacetonate Polyether Adducts: Promising Precursors for MOCVD of GdF₃ Films

The monoglyme {CH3OCH2CH2OCH3} and diglyme {CH3O(CH2CH2O)2CH3} adducts of the gadolinium trishexafluoroacetylacetonate {Gd(hfa)3·monoglyme (1) and Gd(hfa)3·diglyme (2)} have been synthesized and characterized by elemental analyses, mass spectrometry, and infrared spectroscopy. Single-crystal X-ray diffraction studies of Gd(hfa)3·diglyme provide evidence of a mononuclear structure. The thermal analyses revealed high volatility and good thermal stability with a low residue for both compounds. The adducts 1 and 2 have better mass-transport properties and thermal behaviors than conventional rare-earth MOCVD precursors and have been successfully applied to GdF3 film depositions. They represent the first examples of gadolinium precursors that can be used in the liquid phase without decomposition, thus providing constant evaporation rates even for very long deposition times.