Structural and mechanical properties of K[ETH] sub(2)P[ETH] sub(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, MI, Bezkrovnaya, ON, Tkachenko, V F, Grishina, E V, Levchenko, AN, Puzikov, V M, Pritula, I M
• Format: Journal Article
• Language: English
• Published: 01.12.2014
• Subjects: Crystal lattices; Crystals; KDP crystals; Laser damage; Mechanical properties; Nanoparticles; Thresholds; Titanium dioxide
• ISSN: 0232-1300; 1521-4079
• DOI: 10.1002/crat.201400285

Single crystals of KDP crystals with embedded Urea molecules and TiO sub(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 sub(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 sub(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 sub(2) nanoparticles concentration up to 10 super(-4) wt.% and higher resulted in 3-fold reduction of the laser damage threshold of KDP:TiO sub(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 super(-3) wt.% due to crack formation at crystal lattice discontinuities. The grown crystals also have been subjected to dielectric studies. The manuscript is devoted to the microstructure - strength relationship of KDP crystals containing organic molecules and the ones with incorporated TiO sub(2) nanoparticles. It is found that differences in the structure formation mechanism result in the opposite influence of the additives on the mechanical properties and the laser damage threshold of KDP crystal.