MOCVD SYNTHESIS OF PEROVSKITE CaCu_3Ti_4O_(12) FILMS

摘要

The results of a recent study on the deposition of calcium copper titanate, CaCu_3Ti_4O_(12) (CCTO), thin films on lanthanum alluminate, (001) LaA10_3, substrates by metal-organic chemical vapor deposition (MOCVD) are reported. A molten precursor mixture, consisting of the Ca(hfa)_2·tetraglyme, Ti(tmhd)_2(O-iPr)_2, and Cu(tmhd)_2 [Hhfa= 1,1,1,5,5,5-hexafluoro-2,4-pentanedione; tetraglyme= 2,5,8,11,14-pentaoxapenta-decane; Htmhd= 2,2,6,6-tetramethyl-3,5-heptandione; I-Opr = iso-propoxide] precursors, has been employed. The one step route, carried out in the 800-900℃ deposition temperature range, has been found unsuited to the formation of the desired CCTO phase, while a two-step MOCVD process leads to the formation of epitaxial CCTO thin films. Film structural and morphological characterization has been carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM).