Abstract

Recently Ba2HoSbO6, ceramic has been reponed as a potential material for substrate applications for high-temperature superconducting films. As Ba2HoSbO6, is chemically inert with high-temperature superconducting materials. it could be an excellent crucible material for single crystal growth of high-temperature superconducting materials. For such applications high sintered density, homogenous microstructure and good mechanical strength are essential requirements. The principal limitatión of ceramics is their brittleness, i.e., the tendency to fail suddenly with little plástic deformation. This is of particular concern when the material is used in crucible applications. In this work, we have studied microstructural characteristics and mechanical properties of the Ba2HoSbO6 ceramics. Single-phase Ba2HoSbO6 and two other batches of Ba2HoSbO6, containing 1 and 2wt% of CuO as sintering aids, were sintered to study the liquid phase sintering behaviour. Surface morphology and microstructure of sintered materials were studied by scanning electrón microscopy. XRD and EDX analysis show that there are no traces of impurity phases due to, up to 1 wt%, CuO addition in Ba2HoSbO6 samples. SEM micrographs reveal that CuO addition improves the microstructure and particle size distribution of the Ba2HoSbO6 ceramics. Mechanical hardness was determined by using Vickers indentor and this study shows an improvement in the hardness of the CuO added Ba2HoSbO6 ceramics. Our studies reveal that the liquid phase sintering process, due to CuO addition, facilítate^ the sintering of Ba.HoSbOf, and improves the microstructure and particle size distribution of the Ba2HoSbOh ceramics. An important observation is that higher wt% (> Iwt%) CuO addition destroys the crystallographic structural characteristics of the Ba2HoSbO6. Thus liquid phase sintering of Ba2HoSbO6, ceramic using CuO additives is limited to a máximum of lwt% CuO. The microstructural modifications due to the liquid phase sintering process, consequently, help in improving the densification and mechanical hardness of the Ba2HoSbO6 ceramics.