Preparing tin-doped indium oxide ceramic bulk via explosive consolidation and sintering of nanopowders

The tin-doped indium oxide (ITO) ceramic ultra-dense target is the crucial material in spurting preparation of optical-electric films. The difficulty in target fabrication is due to ITO decomposing at high temperatures. In this paper, commercial ITO nanometer powders are used and are explosively shock consolidated with two different sets and different explosives. Experiment data indicate that the shock velocity should be less than 4000 m/sec, and the shock pressure should be more than 6 and even 12 GPa for obtaining good consolidation. The samples are rapidly sintered at a high temperature after shock treatment. A suitable sinter temperature of ITO nanopowders compacted via explosive consolidation ($\approx$1000$^\circ$C) is determined by a differential thermal analysis. Scanning electron microscope images show that ITO ceramic decomposes and sublimates at a high temperature. The expansion factors of the samples from our experiments and commercial targets obtained by high isostatic pressing (HIP) are measured: $\alpha_l$ = 7.81 $\cdot$ 10$^{-6}$K$^{-1}$ for samples sintered at 1000$^\circ$C, $\alpha_l$ = 8.8 $\cdot$ 10$^{-6}$K$^{-1}$ for samples sintered at 900$^\circ$C, and $\alpha_l$ = 6.89 $\cdot$ $^{-6}$K$^{-1}$ for HIP samples.