US EPA

1453529 

Journal Article 

Synthesis, characterization and thermostability of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III) 

Zhang Teng; Gu Hongwei; Ding Fazhu; Qu Fei; Dai Shaotao 

2012 

Yes 

Journal of Rare Earths
ISSN: 1002-0721 

30 

10 

1041-1047 

10.1016/S1002-0721(12)60176-8 

WOS:000310756200015 

The metal-organic chemical vapor deposition (MOCVD)
technique is a promising process for high temperature superconductor YBa2Cu3O7-delta (YBCO)
preparation. In this technique, the purity, evaporation characteristics and thermostability of
adopted precursors will decide the quality and reproducible results of YBCO film. In the present
report, tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III) (Y(TMHD)(3)) was synthesized by
the interaction of yttrium nitrate hydrate with TMHD in methanol solution, and its structure was
identified by FTIR, H-1 NMR, C-13 NMR and EI-MS spectroscopy. Subsequently, the thermal property
and the kinetics of decomposition were systematically investigated by non-isothermal
thermogravimetric analysis methods (TGA) at different heating rates in streams of N-2, and the
average apparent activation energy of evaporation process was evaluated by the Ozawa, Kissinger
and Friedman methods. The possible conversion function was estimated through the Coats-Redfern
method to characterize the evaporation patterns and followed a phase boundary reaction mechanism
by the contracting area equation with average activation energy of 88.9 kJ/mol. 

Y(TMHD)(3); metal-organic chemical vapor deposition (MOCVD); synthesis; thermostability; rare earths