Structural and mechanical properties of KН 2 PО 4 single crystals with embedded nanoparticles and organic molecules

• Published in: Crystal research and technology (1979) Vol. 49; no. 12; pp. 965 - 974
• Main Authors: Kosinova, A. V., Kolybaeva, M. I., Bezkrovnaya, O. N., Tkachenko, V. F., Grishina, E. V., Levchenko, A. N., Puzikov, V. M., Pritula, I. M.
• Format: Journal Article
• Language: English
• Published: 01.12.2014
• ISSN: 0232-1300; 1521-4079
• DOI: 10.1002/crat.201400285

Single crystals of KDP crystals with embedded Urea molecules and TiO 2 nanoparticles have been grown from aqueous solution by the temperature lowering method. The effect of the organic molecules and nanoparticles on the structural and mechanical properties has been studied. It has been observed that addition of Urea molecules improves laser induced damage threshold and mechanical strength of the crystal, while TiO 2 nanoparticles have the opposite effect. The structure and composition of KDP:Urea crystal are studied by three‐crystal X‐ray diffraction analysis, which reveals the existence of a correlation between the increase of the microhardness value and the change of the crystal lattice parameter. The surface features of KDP:TiO 2 crystals are analyzed by scanning electron microscopy that reveals the presence of quasi‐equidistant growth bands caused by capture of the nanoparticles. It is shown that the rise of TiO 2 nanoparticles concentration up to 10 −4 wt.% and higher resulted in 3‐fold reduction of the laser damage threshold of KDP:TiO 2 relative to pure KDP in [001] and [100] crystallographic directions. It is found that microhardness and fracture toughness decrease at the nanoparticles concentration of 10 −3 wt.% due to crack formation at crystal lattice discontinuities. The grown crystals also have been subjected to dielectric studies.