Structural Features Associated with Twinning in the Growth of Gallium Arsenide Single Crystals by the Czochralski Method

The features of the structure of single crystals LiNbO3:B3+ (0.12 and 0.18 wt %) grown by the Czochralski method from the mixture of different genesis were studied. It was found that boron is able to incorporate into the crystal structure of lithium niobate in a trace amounts (~ 10–4–10–5 wt %), decreasing the concentration of structural defects NbLi. Thus, ordering of structural units of the cation sublattice of lithium niobate crystals grown from a congruent composition melt approach in that of stoichiometric crystals.

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Specific features of the formation of dislocation structure in gallium arsenide single crystals obtained by the Czochralski method

Crystallography Reports ◽

10.1134/s1063774517020201 ◽

2017 ◽

Vol 62 (2) ◽

pp. 275-278

Author(s):

I. B. Parfenteva ◽

B. V. Pugachev ◽

V. F. Pavlov ◽

Yu. P. Kozlova ◽

C. N. Knyazev ◽

...

Keyword(s):

Gallium Arsenide ◽

Single Crystals ◽

Dislocation Structure ◽

Czochralski Method

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Numerical Analysis of Difficulties of Growing Large-Size Bulk β-Ga2O3 Single Crystals with the Czochralski Method

Crystals ◽

10.3390/cryst11010025 ◽

2020 ◽

Vol 11 (1) ◽

pp. 25

Author(s):

Xia Tang ◽

Botao Liu ◽

Yue Yu ◽

Sheng Liu ◽

Bing Gao

Keyword(s):

Crystal Growth ◽

Single Crystals ◽

Czochralski Method ◽

Liquid Interface ◽

Spiral Growth ◽

Growth Time ◽

Large Size ◽

Crystal Diameter ◽

Solid Liquid Interface ◽

Solid Liquid

The difficulties in growing large-size bulk β-Ga2O3 single crystals with the Czochralski method were numerically analyzed. The flow and temperature fields for crystals that were four and six inches in diameter were studied. When the crystal diameter is large and the crucible space becomes small, the flow field near the crystal edge becomes poorly controlled, which results in an unreasonable temperature field, which makes the interface velocity very sensitive to the phase boundary shape. The effect of seed rotation with increasing crystal diameter was also studied. With the increase in crystal diameter, the effect of seed rotation causes more uneven temperature distribution. The difficulty of growing large-size bulk β-Ga2O3 single crystals with the Czochralski method is caused by spiral growth. By using dynamic mesh technology to update the crystal growth interface, the calculation results show that the solid–liquid interface of the four-inch crystal is slightly convex and the center is slightly concave. With the increase of crystal growth time, the symmetry of cylindrical crystal will be broken, which will lead to spiral growth. The numerical results of the six-inch crystal show that the whole solid–liquid interface is concave and unstable, which is not conducive to crystal growth.

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The Gold Sulfates MAu(S04)2 (M = Na, K, Rb)

Zeitschrift für Naturforschung B ◽

10.1515/znb-2001-1215 ◽

2001 ◽

Vol 56 (12) ◽

pp. 1340-1343 ◽

Cited By ~ 8

Author(s):

Mathias S. Wickleder ◽

Oliver Büchner

Keyword(s):

Sulfuric Acid ◽

Single Crystals ◽

Crystal Structures ◽

Structural Features ◽

Monovalent Cations ◽

Coordination Numbers ◽

Square Planar ◽

Oxygen Atoms

AbstractThe evaporation of a solution of Au(OH)3 and Na2So4 in conc. sulfuric acid led to yellow single crystals of NaAu(SO4)2 (monoclinic, P21/n, Z = 2, a = 469.1, b = 845.9, c = 831.2 pm, β = 95.7°). Analogous procedures with K2SO4 or Rb2SO4 instead of Na2SO4 yielded single crystals of KAu(SO4)2 (monoclinic, C2/c, Z = 4, a = 1109.8, b = 724.2, c = 941.1 pm, β = 118.4°) and RbAu(S04)2, respectively, (triclinic, P1̄, Z = 1, a = 423.6, b = 497.5, c = 889.0 pm, a = 76.4°, β = 88.4°, γ = 73.5°). Although the crystal structures of the three sulfates are not isotypic they show similar structural features: The gold atoms are coordinated by four oxygen atoms in a square planar manner. These oxygen atoms belong to four SO42- ions which link the [AUO4] units to infinite chains according to 1∞[Au(SO4)4/ 2]- . These chains are connected via the monovalent cations which show coordination numbers of 6 (Na+), 10 (K+) and 12 (Rb+), respectively.

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