CVD Precursor Design Strategies for HTS Materials

Alkaline Earth P-Diketonate Lewis Base Adducts  

One approach to avoiding intermolecular agglomeration is the additional coordination of the alkaline earth metal ions with neutral ligands [110]. Addition of Lewis bases such as free ligand, tetrahydrofuran, ammonia, or amines to the carrier gas has afforded some improvement in vapor pressure characteristics of the most commonly used strontium and barium MOCVD precursors, Sr(dpm)2 and Ba(dpm)2 [111-119]. These effects may be due to saturation of the Lewis acidic metal centers with the gaseous bases, thereby increasing precursor vapor pressure and stability in a transient fashion. 

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