| Popis: |
The deposition of lead zirconate titanate (PbZr[sub x]Ti[sub 1]-[sub x]O[sub 3]) thin films by organometallic chemical vapor deposition (OMCVD) is reported using the new precursor triethyllead tert-butoxide (TELBUT) together with titanium tetra-tert-butoxide (TTB) and zirconium tetra-tert-butoxide (ZTB). TELBUT and the analogous compound triethyllead isopropoxide were synthesized and were found to be thermally stable at room temperature but decomposed when exposed to daylight; for TELBUT the photolysis products are different for the pure compound and solutions in toluene-d[sub 8]. TELBUT started to decompose exothermically around 138 [degrees]C in a differential scanning calorimeter, giving metallic lead. OMCVD experiments showed that, in the absence of additional oxygen, TELBUT gave metallic lead. Lead titanate (PbTiO[sub 3]) could be formed at temperatures between 550 and 700[degrees]C in the presence of oxygen and titanium tetraisopropoxide. Without oxygen, only lead and titanium dioxide were formed. PbZr[sub x]Ti[sub 1]-[sub x]O[sub 3] thin films were deposited using TTB, ZTB, and TELBUT in the presence of oxygen at 700 [degrees]C. Ferroelectric films with good crystallinity and high values for the polarization were obtained with the new precursor system. 26 refs., 3 figs. |
Plný text