X ray topography is a tecnique that comprises topography and X-ray diffraction.The term topography refers to a detailed description and mapping of physical features in a region. In the context of x-ray diffraction,topographic methods are used to survey the lattice structure and imperfections in crystalline materials. The method and procedure used depend largely on the density of defects present and the nature of the crystalline material to be examined, but all methods share the capability for nondestructive application.