Sintering behavior of ZnO: Mn ceramics fabricated from sol-gel derived nanocrystalline powders

Abstract

Undoped and Mn doped ZnO ceramics, sintered at 1200 degrees C, were produced from sol-gel derived nanocrystalline powders calcined at 750 degrees C. Mn doped powders showed trace amounts of spinel (ZnMn2O4) phase in addition to a dominant zincite phase, while Mn doped ceramics were comprised solely of zincite structure. X-ray mapping of the powders, did not reveal any Mn concentrated areas, indicating that the ZnMn2O4 phase was homogeneously distributed with a very small grain size. The grain size of the undoped powders was around 50 rim, and there was a minor increase in the grain size when powders were doped with Mn. Undoped ceramics exhibited grain sizes distributed in the range 2-10 mu m while Mn doped ceramics displayed slightly smaller grains. Relative densities of the undoped and Mn doped ceramics were measured as 0.695 and 0.950, respectively.