Estimation of Hamaker Constants of Ceramic Materials from Optical Data Using Lifshitz Theory

The Hamaker constants of eight different ceramic materials, 6H‐SiC, tetragonal, partially stabilized ZrO 2 (3% Y 2 O 3 ), β‐Si 3 N 4 , α‐Al 2 O 3 , Y 2 O 3 , sapphire (single‐crystal α‐Al 2 O 3 ), MgO, MgAl 2 O 4 , and fused silica, across air, water, and n ‐dodecane at room temperature and across silica at 2000 K have been calculated from optical data using the Lifshitz theory. Spectroscopic ellipsometry was used to measure the photon energy dependence of the refractive index, n , and the extinction coefficient, k , in the visible and near‐UV range on several important ceramic materials. This relatively simple, nondestructive technique has proved to yield reliable optical data on sintered, polycrystalline materials such as Si 3 N 4 , SiC, ZrO 2 , Al 2 O 3 , and ZnO. For the other materials, Y 2 O 3 , sapphire, MgO, MgAl 2 O 4 , and fused silica, optical data from the literature were used to calculate the Hamaker constants. The calculated Hamaker constants were estimated to be accurate within ±10%.