Preparation of high-density InGaZnO4 target by the assistance of cold sintering

In this study, near stoichiometric InGaZnO4 (IGZO) nano-powders were synthesized by a multistep precipitation method with the ammonia solution used as precipitant at 10 °C. Then cold sintering process (CSP) was applied to benefit the green pellets. In the next step, the green pellets fabricated by CSP and dry pressing process (CP) were pressureless sintered (PLS) at 1200 °C or higher temperature for a scheduled time respectively. The in-situ high temperature optical dilatometric test, XRF, XRD and SEM were carried out and the sintering kinetics was analyzed based on the Master Sintering Curve (MSC) model. The results showed that the holding time for densification of CSP/PLS pellets was about 1 h at 1200 °C, just about 1/5 of CP/PLS ones. MSC model revealed that the sintering activation energy (Qa) of CSP/PLS and CP/PLS were 489.7 KJ /mol and 655.6 KJ /mol respectively. The highest relative density (99.30%) of all sintered pellets was achieved by CSP/PLS process and the optimal process parameters were CSP at 180 °C, 200 MPa and 10 min, and PLS at 1200 °C for 1 h. CSP/PLS effectively reduced the sintering temperature and holding time in comparison with the CP/PLS in this research and previous research.