Three-dimensional birefringence imaging with a microscope tilting stage. II. Biaxial crystals

The technique enables precise three-dimensional birefringence information of optically biaxial materials to be obtained. Equations derived here describe a mathematical model of the tilting-stage system for such crystals in any general orientation. This leads to precise values of the three principal birefringences and the optical orientation. The method is also able to obtain information on preferred orientation in a biaxial polycrystalline material, providing comprehensive information on both optical orientation of crystallites and spatial resolution. In addition, an unknown crystalline material may be identified, or at least classified within a specific group of crystalline materials.

ION-BEAM CONTROL OF THIN-FILM MICROSTRUCTURAL COLUMNAR ANGLE

The microstructural columnar angle of titanium oxide is shown to be rotated towards the vapor direction during oblique, ion-assisted deposition. The effect was found to increase with increasing ion energy, but experiments with the ion beam directed along and perpendicular to the tangent rule direction did not reveal dependence on the angle of incidence of the ions. The technique may allow access to deposition of biaxial materials in a regime where the columns run nearly parallel to the substrate.