scholarly journals Oxide Self-Flux in Optical Floating Zone Crystal Growth of Nickel Niobate (NiNb2O6)

2017 ◽  
Author(s):  
Timothy J. S. Munsie ◽  
Anna Millington ◽  
Graeme M. Luke ◽  
Hanna A. Dabkowska
Keyword(s):  
Phase Diagram ◽  
Crystal Growth ◽  
Melting Temperature ◽  
Niobium Oxide ◽  
Growth Parameters ◽  
Growth Conditions ◽  
Floating Zone ◽  
Liquid Zone ◽  
Small Excess

Growing crystals of nickel niobate (NiNb2O6), we noticed that changing growth conditions allowed our material to enter different areas of the phase diagram. In particular, we found that excess material accumulated within and above the liquid zone. Analysis showed that this was an unincorporated constituent. Changing the ratio of the constituent oxides - an excess of ~4% of either NiO or Nb2O5 gave us the opportunity to investigate changes in zone stability, melting temperature and quality of the resulting crystal. We found that a small excess of nickel oxide decreases the melting temperature significantly, and created the best pseudo-rutile NiNb2O6 crystal studied, while higher amounts of niobium oxide allowed us to stabilize the NiNb2O6 columbite phase. This research reinforces the idea that self-flux as a travelling solvent can significantly impact crystal growth parameters and quality.

Heteroepitaxy of Si, Ge, and GaAs Films on CaF2/Si Structures

1986 ◽  
Vol 67 ◽  
Author(s):  
H. Ishiwara ◽  
T. Asano ◽  
H. C. Lee ◽  
Y. Kuriyama ◽  
K. Seki ◽  
...  
Keyword(s):  
Smooth Surface ◽  
Field Effect Transistors ◽  
Growth Parameters ◽  
Growth Conditions ◽  
Heteroepitaxial Growth ◽  
Gate Electrodes ◽  
Gaas Films ◽  
Temperature And Growth ◽  
Si Films

ABSTRACTRecent progress in the research of heteroepitaxial growth of Si, Ge, and GaAs films on CaF2/Si structures is reviewed. Growth conditions and material properties of the Si/CaF2/Si structures are first discussed. It is shown that such growth techniques as the predeposition technique and the recrystallization method are useful to improve the crystalline quality of Si films on the CaF2/Si structures. Then, device application of the Si/CaF2/Si structure to field effect transistors with epitaxial MIS (metal-insulatorsemiconductor) gate electrodes is described. Finally, epitaxial growth of Ge and GaAs films on the CaF2/Si structure are discussed, in which such growth parameters as the substrate temperature and growth rate are optimized to obtain high-quality films with excellent crystallinity and smooth surface.

Growth Conditions of Erbium-Oxygen-Doped Silicon Grown by MBE

1996 ◽  
Vol 422 ◽  
Author(s):  
J. Stimmer ◽  
A. Reittinger ◽  
G. Abstreiter ◽  
H. Holzbrecher ◽  
Ch. Buchal
Keyword(s):  
Molecular Beam Epitaxy ◽  
Systematic Study ◽  
Molecular Beam ◽  
Growth Parameters ◽  
Light Emitting Diode ◽  
Growth Conditions ◽  
Light Emitting ◽  
Doped Silicon

AbstractWe report on a systematic study of the growth parameters of erbium-oxygen-doped silicon grown by molecular beam epitaxy. The surface quality of the grown layers was measured in situ by RHEED. The samples were characterized by photoluminescence measurements and SIMS. An Er-O-doped Si light emitting diode grown with the optimized parameters is presented.

Mathematical Modeling of Growth Conditions and Interpretation of Phase Diagram for InxGa1-xN Epitaxial Layer

2013 ◽  
Vol 372 ◽  
pp. 70-74 ◽  
Author(s):  
Md. Soyaeb Hasan ◽  
Apurba Kumar Saha ◽  
Md. Rafiqul Islam ◽  
Nowshad Amin
Keyword(s):  
Mathematical Modeling ◽  
Phase Diagram ◽  
Gas Flow ◽  
Epitaxial Film ◽  
Growth Parameters ◽  
Growth Conditions ◽  
Indium Content ◽  
Molar Ratio ◽  
Organic Vapor ◽  
Metal Organic

It is imperative to determine the dependence of the quality and characteristics of the epitaxial film on different growth parameters. A mathematical model has been developed showing the effect of different growth parameters e.g. temperature, TMI and TEG flow rate, molar ratio on epitaxial film. This model is considered for InGaN film on GaN template with an Indium mole fraction up to 0.4 by Metal Organic Vapor Phase Epitaxy (MOVPE). The results obtained from this model has been compared and fitted with experimentally obtained data through XRD, RSM, PL, SEM etc. Finally, a phase diagram has been proposed to interpret the phase separation and Indium content evolution under the influence of growth temperature and precursor gas flow.

INVESTIGATION ON INTERMOLECULAR INTERACTION IN SUPERSATURATION STATE OF CADMIUM SULPHATE MIXED ZINC tris-THIOUREA SULPHATE SOLUTIONS

2014 ◽  
Vol 02 (03n04) ◽  
pp. 1450002 ◽  
Author(s):  
G. G. MULEY ◽  
A. B. NAIK ◽  
A. B. GAMBHIRE
Keyword(s):  
Crystal Growth ◽  
Intermolecular Interaction ◽  
Growth Parameters ◽  
Chemical Properties ◽  
Adiabatic Compressibility ◽  
Growth Conditions ◽  
Ft Ir ◽  
Solid Form ◽  
Physical And Chemical ◽  
And Chemical Properties

Zinc tris-thiourea sulphate (ZTS) is a well known nonlinear optical (NLO) crystal widely used for various NLO applications. The NLO, physical and chemical properties can be modified by adding impurities and/or modifying crystal growth conditions. The impurities present in the growth solution and growth conditions can affect the crystal growth parameters at great extent. Thus, the study on the nature of intermolecular interaction with the dopant in the solution during crystal growth process becomes important. In the present investigation, the ultrasonic velocity was measured in the aqueous solutions of pure and cadmium sulphate mixed ZTS in the supersaturation state at 313.15 K. The thermodynamic parameters such as adiabatic compressibility, inter molecular free length, acoustic impedance and relative associations have been calculated from the ultrasonic data and densities of water and solutions at 313.15 K, and the nature of intermolecular interaction has been discussed. FT-IR spectra of all mixtures in the solid form at room temperature were recorded and the shifts in the absorption peaks corresponding to the functional groups of ZTS have been reported.

Directional Solidification of Mo5Si3-MoSi2 Eutectic

1998 ◽  
Vol 552 ◽  
Author(s):  
S. M. Borowicz ◽  
L. Heatherly ◽  
R. H. Zee ◽  
E. P. George
Keyword(s):  
Phase Diagram ◽  
High Temperature ◽  
Directional Solidification ◽  
Growth Rates ◽  
Eutectic Composition ◽  
Directionally Solidify ◽  
Growth Conditions ◽  
Floating Zone ◽  
Directionally Solidified ◽  
Melting Points

ABSTRACTThe Mo-Si phase diagram exhibits a Mo5Si3-MoSi2 eutectic at the 54% Si composition. Since the terminal phases have comparable melting points and are equidistant from the eutectic composition, there is the possibility of obtaining lamellar microstructures in this system. In addition, if the alloys are directionally solidified, there is the further possibility of obtaining aligned lamellae. In this study, a high temperature (xenon-arc-lamp) optical floating zone furnace is utilized to directionally solidify Mo-Si alloys of the eutectic composition. Growth conditions are systematically varied to investigate their effects on the solidification microstructure. Growth rates and rotation speeds are identified that result in lamellar microstructures.

Equipment for Monitoring and Controlling Rheed-Oscillations

1991 ◽  
Vol 220 ◽  
Author(s):  
M. Larsson ◽  
L. -E. Björklund ◽  
G. V. Hansson
Keyword(s):  
Crystal Growth ◽  
Growth Parameters ◽  
Substrate Surface ◽  
Control Unit ◽  
Atomic Layer ◽  
Fast Response ◽  
Growth Conditions ◽  
High Energy ◽  
Oscillation Control ◽  
Discrimination Level

ABSTRACTA Light Oscillation Control Unit System (LOCUS) has been developed for the purpose of monitoring Reflexion High Energy Electron Diffraction (RHEED) oscillations and to use the oscillations to control the crystal growth with single atomic layer resolution. The system can be used for phase-locked epitaxy, i.e., shutters controlling the growth are actuated when monolayers are completed. To reduce the usual damping of the RHEED-oscillations, the system can also use the method of synchronization of nucleation, i.e., periodically varying the surface supersaturation by changing the substrate surface temperature during each oscillation. Four shutters can be operated automatically and the superlattice composition can be chosen in a number of different ways. LOCUS gives fast response on intensity oscillation maxima and minima beyond a programmable discrimination level. Relevant crystal growth parameters can be changed during the run of the program, which implies that even quasi-periodic superlattices can be grown. There is also a possibility to switch from automatic to manual control. The shutters and substrate heater have been designed to reduce the influence of shifts of the diffraction pattern as the growth conditions are changed.

scholarly journals Atmospheric Pressure Catalytic Vapor Deposition of Graphene on Liquid In and Cu-In Alloy Substrates

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1318
Author(s):  
Maryam A. Saeed ◽  
Ian A. Kinloch ◽  
Brian Derby
Keyword(s):  
Atmospheric Pressure ◽  
Defect Density ◽  
Growth Parameters ◽  
Chemical Vapour ◽  
Growth Conditions ◽  
Growth Time ◽  
Graphene Growth ◽  
Graphene Films ◽  
Reactive Gases

Liquid substrates are great candidates for the growth of high-quality graphene using chemical vapour deposition (CVD) due to their atomically flat and defect free surfaces. A detailed study of graphene growth using atmospheric pressure CVD (APCVD) on liquid indium (In) was conducted. It was found that the effect of the growth parameters on the quality of the graphene produced is highly dependent on the properties of the substrate used. A short residence time of 6.8 sec for the reactive gases led to a high graphene quality, indicating the good catalytic behaviour of In. The role of hydrogen partial pressure was found to be crucial, with monolayer and bilayer graphene films with a low defect density obtained at low PH2 (38.6 mbar), whilst more defective, thicker graphene films with a partial coverage being obtained at high PH2 (74.3 mbar). The graphene deposition was insensitive to growth time as the graphene growth on liquid In was found to self-limit to bilayer. For further investigation, five compositions of Cu-In alloys were made by arc-melting. Graphene was then grown using the optimum conditions for In and the quality of the graphene was found to degrade with increasing Cu wt.%. This work will aid the future optimisation of the growth conditions based upon the substrate’s properties.

Study on TlBr Single Crystal Growth Using Improved Electro Dynamic Gradient Method

2011 ◽  
Vol 415-417 ◽  
pp. 1979-1982
Author(s):  
Zhi Ping Zheng ◽  
Jing Wang ◽  
Lin Quan ◽  
Shu Ping Gong ◽  
Dong Xiang Zhou
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Electrical Properties ◽  
Temperature Gradient ◽  
Growth Conditions ◽  
Single Crystal Growth ◽  
Optical And Electrical Properties ◽  
X Ray Diffraction ◽  
X Ray

Electro Dynamic Gradient (EDG) method was utilized for TlBr crystal growth in this paper. The influence of crystal growth conditions such as temperature gradient and growth rate on optical and electrical properties of grown TlBr crystals was investigated. The quality of TlBr crystals was characterized by infrared (IR) transmittance spectrum, X-ray diffraction, and I-V measurements.

Sign in / Sign up

Export Citation Format

Share Document