Effect of thermal annealing conditions on the microdefect formation in undoped GaAs single crystals grown by Czochralski method

2000 ◽  
Vol 45 (5) ◽  
pp. 821-826 ◽  
Author(s):  
V. T. Bublik ◽  
M. I. Voronova ◽  
A. V. Markov ◽  
K. D. Shcherbachev
Keyword(s):  
Single Crystals ◽  
Thermal Annealing ◽  
Czochralski Method ◽  
Annealing Conditions ◽  
Undoped Gaas

Study of effect of thermal annealing on crystalline perfection of bismuth germanate single crystals grown by low thermal gradient Czochralski method

2002 ◽  
Vol 217 (10) ◽  
Author(s):  
A. Choubey ◽  
G. Bhagavannarayana ◽  
Yu. V. Shubin ◽  
B. R. Chakraborty ◽  
K. Lal
Keyword(s):  
Single Crystals ◽  
Thermal Annealing ◽  
Thermal Gradient ◽  
Czochralski Method ◽  
Bismuth Germanate ◽  
Crystalline Perfection

AbstractBismuth germanate single crystals containing low angle and

Magneto-Optical Study of Martensitic Transition in Ni45Mn36.7In13.3Co5 (at. %) Single Crystals

2015 ◽  
Vol 233-234 ◽  
pp. 225-228 ◽  
Author(s):  
Elena Gan’shina ◽  
Andrey Novikov ◽  
Volodymyr Chernenko ◽  
J. Barandiaran ◽  
Eduard Cesari ◽  
...  
Keyword(s):  
Single Crystals ◽  
Kerr Effect ◽  
Cold Water ◽  
Czochralski Method ◽  
The Other ◽  
Martensitic Transition ◽  
Optical Study ◽  
Scanning Calorimetry ◽  
Characteristic Temperatures ◽  
Annealing Conditions

Transverse Kerr effect (TKE) was used to study magneto-optical (MO) properties of Ni45Mn36.7In13.3Co5 (at.%) single crystals. A single crystalline ingot of such composition was grown by the Czochralski method. One series of samples was quenched into cold water (WQ) and the other series after quenching was heated at 770 K for 20 min and slowly cooled to assure a complete atomic order (SC). Accordingly to differential scanning calorimetry (DSC), magnetic and magneto-optical (MO) measurements, WQ samples exhibit well-defined martensitic transition (MT), but the SC samples do not show MT. It is found that TKE for WQ samples shows the following features (i) MO signal is well pronounced far below the martensitic transition in spite of a weak magnetization of martensitic phase; (ii) the characteristic temperatures of martensitic transition differ from those for the bulk and depend on annealing conditions; (iii) MO spectra profile do not change significantly during the martensitic transition and is similar but not identical with that for Ni50Mn35In15 thin films and Ni43.7Mn43.6In12.7 ribbons measured before; (iv) MO signal is anisotropic.

scholarly journals Кристаллофизическая модель ионного переноса в нелинейно-оптических кристаллах KTiOPO-=SUB=-4-=/SUB=-

2018 ◽  
Vol 60 (4) ◽  
pp. 706
Author(s):  
Н.И. Сорокин ◽  
Ю.В. Шалдин
Keyword(s):  
Ionic Conductivity ◽  
Impedance Spectroscopy ◽  
Single Crystals ◽  
Thermal Annealing ◽  
High Resistance ◽  
Nonlinear Optical ◽  
Ionic Transport ◽  
Czochralski Method ◽  
One Dimensional ◽  
Principal Axes

AbstractThe ionic conductivity along the principal axes a, b, and c of the unit cell of the nonlinear-optical high-resistance KTiOPO_4 single crystals (rhombic syngony, space group Pna 2_1), which are as-grown and after thermal annealing in vacuum, has been investigated by the method of impedance spectroscopy. The crystals were grown from a solution-melt by the Czochralski method. The as-grown KTiOPO_4 crystals possess a quasi-one-dimensional conductivity along the crystallographic c axis, which is caused by the migration of K^+ cations: σ_║ c = 1.0 × 10^–5 S/cm at 573 K. Wherein the characteristics of the anisotropy of ionic conductivity of the crystals is equal to σ_║ c /σ_║ a = 3 and σ_║ c /σ_║ b = 24. The thermal annealing at 1000 K for 10 h in vacuum increases the magnitude of σ_║ c of KTiOPO_4 by a factor of 28 and leads to an increase in the ratio σ_║ c /σ_║ b = 2.1 × 10^3 at 573 K. A crystal-physical model of ionic transport in KTiOPO_4 crystals has been proposed.

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

Crystals ◽  
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.

Fabrication and evolution of nanostructure in Al2O3 single crystals by Zn+ ion implantation and thermal annealing

Vacuum ◽  
2013 ◽  
Vol 89 ◽  
pp. 132-135
Author(s):  
J.X. Xu ◽  
X.H. Xiao ◽  
F. Ren ◽  
X.D. Zhou ◽  
G.X. Cai ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystals ◽  
Thermal Annealing

Growth of nearly perfect alkali halide single crystals by Czochralski method and their characterisation

1982 ◽  
Vol 56 (1) ◽  
pp. 125-131 ◽  
Author(s):  
Krishan Lal ◽  
R.V.Anantha Murthy ◽  
S.K. Halder ◽  
Bhanu Pratap Singh ◽  
Vijay Kumar
Keyword(s):  
Single Crystals ◽  
Alkali Halide ◽  
Czochralski Method

Effects of thermal annealing on semi‐insulating undoped GaAs grown by the liquid‐encapsulated Czochralski technique

1985 ◽  
Vol 57 (6) ◽  
pp. 2203-2209 ◽  
Author(s):  
A. K. Chin ◽  
I. Camlibel ◽  
R. Caruso ◽  
M. S. S. Young ◽  
A. R. Von Neida
Keyword(s):  
Thermal Annealing ◽  
Czochralski Technique ◽  
Undoped Gaas

Growth and characterization of large-size bismuth germanate single crystals by low thermal gradient Czochralski method

1999 ◽  
Vol 197 (4) ◽  
pp. 865-873 ◽  
Author(s):  
R.V Anantha Murthy ◽  
M Ravikumar ◽  
A Choubey ◽  
Krishan Lal ◽  
Lyudmila Kharachenko ◽  
...  
Keyword(s):  
Single Crystals ◽  
Thermal Gradient ◽  
Czochralski Method ◽  
Bismuth Germanate ◽  
Large Size
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