Fabrication of Segments for ZnO-Based Tube Ceramic Targets by the Spark Plasma Sintering Method

In this article, problems associated with the fabrication of ZnO-based ceramics in the form of large-diameter hollow cylinders with a large ratio of height h to wall thickness ∆r (h/∆r ≥ 3) by the spark plasma sintering (SPS) method were studied. The design of the press-form is proposed, which ensures the reduction in temperature gradients along the inner and outer surfaces of the hollow cylindrical sintered body and, as a result, the achievement of a high-density uniformity of the sintered body over its volume. A hollow cylindrical ZnO-based ceramic sample considered as segments of TCO tube targets with outer diameter D = 72 mm, inner diameter d = 47 mm, and height h = 36 mm were fabricated. The sample had a relative density of more than 98.5% of the theoretical density for a given composition with a minimal density inhomogeneity along the height of the sample. The microstructure of the obtained ceramics was studied using the SEM and XRD methods.