Orientation of Single Crystals
by X-Ray DiffractionA wide range of technological products are based on the use of single crystals. Electronic properties of single crystals are employed in the semiconductor industry, magnetic properties of single crystals are employed to build magnetic storage devices, mechanical properties (e.g., yield strength) and chemical properties (e.g., corrosion rate) of single crystals are employed in materials science. Even the understanding of many polycrystalline materials has been gained by studies of single crystals.
In most cases, the properties of a single crystal are not only a function of the type and quality of the crystal, but strongly dependent on its orientation. The determination of single crystal orientation thus represents an essential step towards the successful use of single crystals in technological applications. A clear understanding of the crystal's structure and the precise knowledge of its orientation often help greatly to optimize the crystal's performance.
Even though the "etch-pit method" can be used in some applications to determine the orientation of flat crystal sides of known Miller indices, X-ray diffraction has become the universal method for orientation studies. The three main methods employed, Back Reflection Laue, Transmission Laue and Diffractometer, not only provide accurate information about the orientation of the crystal, but allow to determine its entire structure. Furthermore, all three methods provide information about the quality of the single crystal and possible deformation.
Analysis Services Provided by CAMET Research, Inc.
CAMET Research, Inc. is an independent materials characterization laboratory, which has been providing X-ray analysis services since 1984. A range of Laue cameras with various rotatable sample stages is employed for single crystal orientation studies. A high precision orientation diffractometer, a diffracted beam diffractometer, a parallel beam diffractometer and various wide angle diffractometers are set up for single crystal studies. Rocking curve experiments are employed to determine crystal quality. Interchangeable X-Y-Z positioning tables, rotating stages and customized sample mounts allow the probing of large and oddly shaped crystals. Computer programs for Laue pattern analysis and simulation are used to minimize the number of experiments necessary for the positive determination of the crystal structure and orientation.
CAMET Research, Inc. - 6409 Camino Vista #F, Goleta, California 93117 - Tel. (805) 685-1665 - Fax (805) 685-9082 - E-mail: camet@camet-lab.com