Habit modification in L-arginine doped potassium dihydrogen phosphate crystal growth under applied electric field

2020 ◽  
Author(s):  
Ashwini Mahadik ◽  
P. H. Soni ◽  
Ketan Chaudhari
Keyword(s):  
Crystal Growth ◽  
Electric Field ◽  
Applied Electric Field ◽  
Potassium Dihydrogen Phosphate ◽  
Dihydrogen Phosphate ◽  
Potassium Dihydrogen ◽  
Habit Modification

Effect of optical activity on electro-optic measurements in crystals of the potassium dihydrogen phosphate family

2012 ◽  
Vol 45 (5) ◽  
pp. 950-962 ◽  
Author(s):  
Marek Izdebski
Keyword(s):  
Electric Field ◽  
Optical Activity ◽  
Point Group ◽  
Potassium Dihydrogen Phosphate ◽  
Dihydrogen Phosphate ◽  
Linear Quadratic ◽  
Potassium Dihydrogen ◽  
Electro Optic ◽  
Effective Coefficients ◽  
New Interpretation

Crystals of the potassium dihydrogen phosphate family in their paraelectric phase belong to point group \overline 4 2m, which allows for natural optical activity and electric field-induced optical activity related to the linear and nonlinear electrogyration effects. This work presents a theoretical analysis of the influence of these effects on measurements of the linear, quadratic and fourth-order electro-optic coefficients. Both the polarimetric technique and a method based on Michelson interferometry are considered. A number of configurations of the light path and the electric field directions were analyzed, and it was found that the influence, when it appears, is usually negligibly small. Thus, no previously reported experimental data need a new interpretation. However, in future measurements of some effective coefficients of the quadratic electro-optic effect using the dynamic polarimetric technique, the contribution of the quadratic electrogyration may no longer be negligible after improving the resolution from 10−21to 10−22 m2 V−2. This work also shows that the quadratic electrogyration described by the β31coefficient may be decoupled from the linear and quadratic electro-optic effects in measurements performed by the polarimetric method.

Thermodynamics of Potassium Dihydrogen Phosphate Growth: Baseline for Understanding Single-Crystal Formation

2012 ◽  
Vol 581-582 ◽  
pp. 727-730 ◽  
Author(s):  
Xu Zhang ◽  
De Xiang Jia ◽  
Hua Xie
Keyword(s):  
Crystal Growth ◽  
Surface Energy ◽  
Surface Chemistry ◽  
Thermodynamic Description ◽  
Potassium Dihydrogen Phosphate ◽  
Dihydrogen Phosphate ◽  
Crystal Formation ◽  
Kdp Crystal ◽  
Potassium Dihydrogen ◽  
Effect Of Surface

The geometric shape of a crystal can be simulated via a thermodynamic model using breaking bond energy calculations. When this model was applied to the case of the KDP crystal, a thermodynamic description of the KDP crystal growth was successfully developed, which was consistent with experimental observations. Additionally, the effect of surface chemistry on the morphology of the KDP crystal was also investigated using the model based on the surface energy of the KDP crystal. These results confirm that bond making and breaking strongly influence the thermodynamic morphology of the KDP crystal during the crystallization.

scholarly journals Modeling the mass transfer processes in the growth of KDP crystals from solution

2019 ◽  
Vol 21 (1) ◽  
pp. 26-34
Author(s):  
N. A. Verezub ◽  
V. L. Manomenova ◽  
A. I. Prostomolotov
Keyword(s):  
Mathematical Model ◽  
Aqueous Solution ◽  
Mass Transfer ◽  
Crystal Growth ◽  
Potassium Dihydrogen Phosphate ◽  
Dihydrogen Phosphate ◽  
Potassium Dihydrogen ◽  
Transfer Processes ◽  
Mass Transfer Processes ◽  
Kdp Crystals

Finding the conditions of high-speed single crystal growth with an appropriate quality is a priority for the industrial production of crystalline materials. Crystals of potassium dihydrogen phosphate (KDP) are important optical materials, they are grown from an aqueous solution and an increase in the rate of growth and quality of a single crystal is of great practical importance.In this paper, mathematical simulation of hydrodynamic and mass transfer processes in growing KDP crystals is performed. The flow and mass transfer are modeled within the framework of continuous medium, which is considered as an aqueous solution of a special salt — potassium dihydrogen phosphate. This salt dissolves in water to a saturation level at a high temperature. Then, such supersaturated solution is used to grow crystals at lower temperatures in non-flowing and flowing crystallizers. The mathematical model is considered in a conjugate formulation with allowance for mass transfer in the«solution—crystal» system. Local features of hydrodynamics and mass transfer in a solution near the surface of a growing crystal are determined, which can affect on the local (for a particular place and direction) crystal growth rate and the formation of defects. The requirements to the crystallizers that provide the «necessary» hydrodynamics in the solution are discussed. Its validation is shown for the flow around a long horizontal plate simulating the growing facet of the crystal. The rate of precipitation of salt was evaluated by the proposed mathematical model, which matches the calculation of solution flow according to the Navier-Stokes equations for an incompressible fluid with a thermodynamic condition for the normal growth of a face under conditions of two-dimensional nucleation. The action of the flowing crystallizers was analyzed for various solution inflows (axial and ring) and its outflow through the axial bottom hole.

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