Abstract: Disclosed herein is a multilayer sintered ceramic body comprising at least one first layer comprising poly crystalline YAG, wherein the at least one first layer comprising poly crystalline YAG comprises pores wherein the pores have a maximum size of from 0.1 to 5 ?m, at least one second layer comprising alumina and zirconia wherein the zirconia comprises at least one of stabilized and partially stabilized zirconia, and at least one third layer comprising at least one of YAG, alumina, and zirconia, wherein an absolute value of the difference in coefficient of thermal expansion (CTE) between the at least one first, second and third layers is from 0 to 0.75×10-6/° C. as measured in accordance with ASTM E228-17, wherein the at least one first, second and third layers form a unitary, multilayer sintered ceramic body. Methods of making are also disclosed.

Abstract: Disclosed herein are plasma chamber components that comprise a ceramic sintered body comprising at least one first layer comprising a surface having a surface area and at least one crystalline phase of from 90% to 99.8% by volume of poly crystalline yttrium aluminum garnet (YAG), at least one second layer comprising alumina and zirconia wherein the zirconia comprises at least one of stabilized and partially stabilized zirconia, and optionally, at least one third layer comprising at least one selected from the group consisting of YAG, alumina, and zirconia.

Abstract: A sintered yttrium oxide body having a total impurity level of 40 ppm or less, a density of not less than 4.93 g/cm3, wherein the sintered yttrium oxide body has at least one surface comprising at least one pore, wherein no pore is larger than 5 ?m in diameter. A process for making the sintered yttrium oxide body is also disclosed.