Shock induced phase change in KCl single crystals: Orientation relations between the B1 and B2 lattices

2009 ◽  
Vol 105 (1) ◽  
pp. 013544 ◽  
Author(s):  
Stefan J. Turneaure ◽  
Y. M. Gupta ◽  
Paulo Rigg
1970 ◽  
Vol 9 (56) ◽  
pp. 269-277 ◽  
Author(s):  
T. E. Osterkamp ◽  
A. H. Weber

The Workman-Reynolds effect was investigated during the phase change of dilute (about 2 × 10-4 N) KCl solutions into single crystals of ice. The ice crystals were oriented with the c-axes either parallel or perpendicular to the growth direction. The solute distribution in the liquid phase. near the interface (within 10 mm), was obtained with a wire-type conductivity cell. For a crystal growth rate 8.8 μm/s the freezing potentials were + 10.0 V and + 6.0 V and the specific charge séparations were 1.3 ± 0 1 × 10-6 C/g of ice and 1 4 ± 0.1 × 10-6 C/g of ice for growth parallel and perpendicular. Respectively, to the c-axes of the ice crystals . The equilibrium solute distribution coefficient was found to be 4 × 10-3 for KCl solutions for both crystal orientations. An “apparent” (because of convection in the liquid phase) distribution coefficient ranged from 0.031- 0.074. The “apparent” diffusion coefficients ranged from 1.3–4.9 × 10-3 mm2/s and varied linearly with growth rate. The ionic distribution coefficients. K+ and K-, were approximately K+ - K- = - 2 × 10-5 and K+ + K - = 8 × 10-3 for the KCl solutions.


1970 ◽  
Vol 9 (56) ◽  
pp. 269-277
Author(s):  
T. E. Osterkamp ◽  
A. H. Weber

The Workman-Reynolds effect was investigated during the phase change of dilute (about 2 × 10-4 N) KCl solutions into single crystals of ice. The ice crystals were oriented with the c-axes either parallel or perpendicular to the growth direction. The solute distribution in the liquid phase. near the interface (within 10 mm), was obtained with a wire-type conductivity cell. For a crystal growth rate 8.8 μm/s the freezing potentials were + 10.0 V and + 6.0 V and the specific charge séparations were 1.3 ± 0 1 × 10-6 C/g of ice and 1 4 ± 0.1 × 10-6 C/g of ice for growth parallel and perpendicular. Respectively, to the c-axes of the ice crystals . The equilibrium solute distribution coefficient was found to be 4 × 10-3 for KCl solutions for both crystal orientations. An “apparent” (because of convection in the liquid phase) distribution coefficient ranged from 0.031- 0.074. The “apparent” diffusion coefficients ranged from 1.3–4.9 × 10-3 mm2/s and varied linearly with growth rate. The ionic distribution coefficients. K+ and K-, were approximately K+ - K- = - 2 × 10-5 and K+ + K - = 8 × 10-3 for the KCl solutions.


2006 ◽  
Vol 39 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Heidrun Sowa ◽  
Hans Ahsbahs

A high-pressure cell for single-crystal investigations requires large opening angles. If it does not contain any beryllium but only two diamonds mounted on steel backing plates, normally only lower pressures can be attained without risk of disruption of the diamond anvils [Ahsbahs (2004).Z. Kristallogr.219, 305–308]. In order to enable pressures up to at least 10 GPa, specially shaped anvils were designed. In a first study with such anvils, the high-pressure behaviour of zincite ZnO was investigated up to the transition pressure of about 9.5 GPa. A slight decrease of the axial ratioc/awith increasing pressure was observed. The fit of the Birch–Murnaghan equation of state gave a bulk modulusK= 146.5 (8) GPa with a fixed pressure derivativeK′ = 4. During the phase transformation, the single crystals were destroyed. The pronounced preferred orientation of the obtained material, however, enabled the determination of the orientation relations between the low-pressure wurtzite-type and the high-pressure NaCl-type phase. The orientation relations are similar to those in CdS and CdSe.


2021 ◽  
Vol 71 (10) ◽  
pp. 827-837
Author(s):  
Kyoung Hwa KIM ◽  
Gang Seok LEE ◽  
Hyung Soo AHN* ◽  
Jae Hak LEE ◽  
Young Tea CHUN ◽  
...  

Author(s):  
Lucien F. Trueb

A new type of synthetic industrial diamond formed by an explosive shock process has been recently developed by the Du Pont Company. This material consists of a mixture of two basically different forms, as shown in Figure 1: relatively flat and compact aggregates of acicular crystallites, and single crystals in the form of irregular polyhedra with straight edges.Figure 2 is a high magnification micrograph typical for the fibrous aggregates; it shows that they are composed of bundles of crystallites 0.05-0.3 μ long and 0.02 μ. wide. The selected area diffraction diagram (insert in Figure 2) consists of a weak polycrystalline ring pattern and a strong texture pattern with arc reflections. The latter results from crystals having preferred orientation, which shows that in a given particle most fibrils have a similar orientation.


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