The vapor pressures and vapor molecular weights of the copper and yttrium b
eta -diketonate MOCVD precursors CU(C11H19O2)(2) (c) and Y(C11H19O2)(3) (c)
were measured by a;torsion-effusion/mass-loss method in the ranges (346 to
375) K and (361 to 387) K, respectively. The molecular weight data indicat
e that the saturated vapors of both precursors are highly monomeric. Vapor
pressures, estimated to be accurate within 5%, are presented in equation fo
rm for reliable extrapolation to higher temperatures. The results are compa
red with other determinations in the literature.