Abstract: The principle of Rotating specimen for determining crystal Orientation XRD (RO-XRD) testing method presented in
this paper is rotating the specimen along its surface normal axle during the θ scanning to increase the chances for the normal axle of a crystal
plane to cross the diffraction plane on a powder X-ray diffractionmeter. Orientated polycrystal, quasi-single crystal or single-crystal materials can
be easily distinguished, and the crystal quality of quasi-single and orientated crystal materials in processing can be picturesquely assessed
by this method. The deviation angle of the crystal plane from the macro surface and the scattering degree of the crystal orientation of single
crystal, quasi single crystal and orientated crystal materials can be measured, which makes it possible to define the three dimensional crystal
plane directions of a single crystal material by this method. The RO-XRD method is simple, quick, adaptable and precise for measuring crystal
orientation, therefore, it has wide potential applications in the fields related to electronic, optical, magnetic materials and engineering
materials.

Key words: crystal material, crystal orientation, X-ray diffraction