Impact of mechanical activation of reactant powders on the solid-state-densification of Zn1-xLixO and Zn0.7Li0.28Mg0.02O ceramics

Abstract

This paper presents effects of powder mechanical activation and controlled sintering on the densification properties of ZnO ceramics with Lithium (Li) and Magnesium (Mg) dopants. Dense bodies of Zn1-xLixO and Zn0.7Li0.28Mg0.02O ceramics were prepared via solid-state-reaction of mechanically activated mixtures of ZnO, Li2CO3 and MgO reactant raw powders. The density, surface microstructure, porosity and phase purities of the ceramics were investigated with a Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) techniques. The study highlights mechanical activation processes such as milling, calcination and compaction steps that are needed to overcome complicated interactive reactions during conventional sintering of Zn1-xLixO and Zn0.7Li0.28Mg0.02O ceramics that have been reported to show ferroelectric behavior. The results show that, densely packed single phase Zn1-xLixO and Zn0.7Li0.28Mg0.02O ceramics with average relative density values above 96% and single phase hexagonal wurtzite crystalline structure were achieved at a sintering temperature of 1000 °C for 2 h in air.

Keywords

• Densification
• Doping
• Hexagonal-wurtzite-structure
• Solid-state-reaction
• Sintering
• ZnO