Blocks and residual stresses in sapphire rods of different crystallographic orientations grown by the Stepanov method

• Published in: Crystallography reports Vol. 60; no. 3; pp. 377 - 383
• Main Authors: Krymov, V. M., Nosov, Yu. G., Bakholdin, S. I., Maslov, V. N., Shul’pina, I. L.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-05-2015
• Subjects: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CRYSTAL GROWTH; CRYSTAL STRUCTURE; Crystallography and Scattering Methods; INVERTED STEPANOV METHOD; ORIENTATION; Physics; Physics and Astronomy; PROBABILITY; Real Structure of Crystals; RESIDUAL STRESSES; RODS; SAPPHIRE; Slip System; Residual Stress; Block Structure; Crystallography Report; Sapphire
• ISSN: 1063-7745; 1562-689X
• DOI: 10.1134/S1063774515020145

The formation of blocks in shaped sapphire rods of two crystallographic orientations has been investigated. It is shown that, when growth occurs in the direction of the optical
c
axis, blocks are formed with a higher probability than in the case of growth in the
a
direction. A model of formation of blocks in rods of different orientations is proposed. The distribution of residual stresses over sapphire rod cross sections is measured by conoscopy. It is found that stresses increase from the middle of a rod to its periphery and reach 20 MPa.