Xun Sun

Effect of EDTA on the light scatter in KDP crystal

KDP crystals with different concentrations of EDTA in solution were grown. Light scatter was detected with ultramicroscopic method. It has been proven that light scatter in KDP crystal aggravates with the increasing concentration of EDTA in the growth solution. The increase with light scatter occurs since EDTA inhibits the growth of KDP crystal at high concentration, which results in the formation of mother liquid inclusions, which in turn causes light scatter. The density, size and shape of light scatter are varied within different sectors of the KDP crystal. The mechanism of the effect is discussed.

Effects of anions on rapid growth and growth habit of KDP crystals

Abstract The synthesis of KDP from its raw material has been found exist in the growth solution. In the crystal growth experiment, significant extension of specific faces was observed at low dopant concentration. At high doping concentration, the growth rate of the whole crystal decreased with no significant habit modification. The inhibiting effects of phosphite and other H-bonding anionic ions on the growth of pyramidal faces are discussed. Rapid growth rate experiments have been carried out with purified material and an averaged growth rate of 18.6mm/day was obtained.

Study on the liquid inclusion induced light scatter in KDP crystal

In this paper we describe the formation of liquid inclusion induced light scatter in potassium dihydrogen phosphate crystal. The measurements were done by ultra-microscopy, TEM and AFM. The dimension of the scatter and the composition have been measured and a mechanism formation of the liquid inclusion induced scatter is proposed and discussed.

Cluster Formation in Solid–Liquid Interface Boundary Layers of KDP Studied by Raman Spectroscopy

The cluster formations in solid-liquid interface boundary layers of KDP crystals have been studied by Raman spectroscopy and ab initio cluster calculations with the density-functional theory. The calculations are made on H 2 PO 4 , H 4 P 2 O 8 , and H 4 P 4 O 16 clusters, which model the cluster structure in different growth layers. Excellent agreement has been achieved between vibrational frequencies predicted by theory and those observed in experiments. The present results also show that the desolvation process of polymer clusters takes place within the characteristic boundary layers. The growth unit of crystal growth is identified as H 4 P 2 O 8 dimer cluster.

The second-harmonic-generation property of GdCa4O(BO3)3 crystal with various phase-matching directions

Abstract The method to determine the spatial configuration of GdCa4O(BO3)3 (GdCOB) crystal is introduced. Samples are cut in and out of principal planes for type I phase matching. Their second-harmonic-generation (SHG) conversion efficiency is measured by a mode-locked Nd:YAG laser. The intracavity doubling frequency of GdCOB crystal is reported for the first time. At the incident pump power of 10 W, the 532 nm output reaches 1.22 W with the (113.2°, 47.4°)-cut sample. In conclusion, the (113.2°, 47.4°)-cut sample shows more excellent SHG property than those cut in other directions.

Supernormal optical characteristics in doped quaternary ammonium salt KDP crystals

Abstract Potassium dihydrogen phosphate, KH 2 PO 4 (KDP) crystals with different concentrations of quaternary ammonium salt in solution were grown. In this paper, unusual transmittance ratio properties of KDP are reported. The transmittance ratio is smaller than unity at some locations. These results indicate that the plane wave effect and optical activity are highly displaced in KDP crystals, and the effect is varies in three-dimensional positions.

In-Line Bulk Concentration Measurement by Method of Conductivity in Industrial KDP Crystal Growth from Aqueous Solution

.The conductivity of KH 2 PO 4 (KDP) aqueous solutions with varying saturation temperature from 28.5°C to 41.8°C was measured in the temperature range of 30°C to 40°C. Its proposed that the conductivity of KDP solutions can be expressed by L=L 0 +b 1 T+b 2 T 2 . This relation can be interpreted by Falkenhagens (1971) conductivity model of high concentration electrolyte solution. The experimental data agrees well to the relation with an accuracy of super-saturation within ±0.03g KDP/100g water (±0.10% relative super-saturation).

Effect of pyrophosphate on the light scatter in KDP crystal

Pyrophosphate doped potassium dihydrogen phosphate (KDP) crystal was grown from aqueous solution by the temperature lowering method. Light scatter in KDP crystal was detected with the ultramicroscopic method. The light scatter in KDP crystal was aggravated when pyrophosphate was doped into the growth solution, which was distributed ununiformly in prism and pyramidal sectors of KDP crystal. Different effects of pyrophosphate on prism and pyramidal sectors of KDP crystal can explain this case. The transmission in this crystal was measured, showing that pyrophosphate affects the transmission evidently.

Modification of pyroelectric crystal TGS using thermodynamic theory

Abstract Based on the Devonshire thermodynamic theory, the relationship λ χ = Ps/C can be regarded as a method to increase the pyroelectric material figure of merit of ferroelectric crystals. Several modified TGS crystals doped with urea or co-doped with urea and other dopants have been grown. The effect of the urea dopant on crystal growth and pyroelectric properties was investigated. The pyroelectric figures of merit M ( λ ϵ ) of the doped TGS crystals are obviously higher than those of pure TGS. Furthermore, the variations of λ χ and Ps/C as a function of temperature for these doped TGS single crystals were measured, and analyzed according to the Devonshire thermodynamic model.

Abnormal optical properties in doped H3BO3 KDP crystals

Abstract Potassium dihydrogen phosphate (KDP) crystals with different concentrations of H 3 BO 3 in solution were grown. Light scatter was detected with ultramicroscopic method. The distinct characteristics of biaxial crystals caused by inherent stress can be found by using cone-shaped interference in the samples. In this paper, abnormal transmittance ratio properties are reported in doped H 3 BO 3 KDP crystals.