The thermal stability and suitability of synthesized yttrium metallorganic complexes were studied for chemical vapor deposition use by thermogravimetric analyses. The phase purity of the synthesized complexes was analyzed by powder X-ray diffraction and mass spectral techniques. The equilibrium vapor pressure of screened yttrium complexes was measured over a temperature range 319–475 K using the horizontal thermogravimetric analyzer as a transpiration apparatus. Model and model-free solid-state kinetic methods were applied to non-isothermal and isothermal measurements to derive kinetic characteristics of the sublimation/evaporation process of selected yttrium vapor sources in the conversion range of 0.1 < 0.7. The relevant results are discussed in detail.