- In chemistry and
mineralogy, a crystal is a solid in which the constituent atoms,
molecules, or ions are packed in a regularly ordered, repeating pattern
extending in all three spatial dimensions. The word crystals originates
from the Greek word "Krystallos" meaning clear ice, and once referred
particularly to quartz, rock crystal.
- Crystalline structures
occur in all classes of materials, with all types of chemical bonds.
Almost all metal exists in a polycrystalline state; amorphous or
single-crystal metals must be produced synthetically, often with great
difficulty.
- The process of forming
a crystalline structure from a fluid or from materials dissolved in the
fluid is often referred to as crystallization.
- Ionically bonded
crystals can form upon solidification of salts, either from a molten
fluid or when it condenses from a solution.
- Covalently bonded
crystals are also very common, notable examples being diamond, silica,
and graphite.
- Polymer materials
generally will form crystalline regions, but the lengths of the
molecules usually prevents complete crystallization.
- Weak Van der
Waals forces can also play a role in a crystal structure; for example,
this type of bonding loosely holds together the hexagonal-patterned
sheets in graphite.
- The defining property
of a crystal is its inherent symmetry, by which we mean that under
certain operations the crystal remains unchanged.
- There are a few crystal
structures, notably the perovskite structure, which exhibit
ferroelectric behaviour.
- This is analogous
to ferromagnetism, in that, in the absence of an electric field during
production, the ferroelectric crystal does not exhibit a polarisation.
Upon the application of an electric field of sufficient magnitude, the
crystal becomes permanently polarised.
- Single crystal silicon
ingots are created with a crystal pulling process originally developed
by Mitsubishi Materials Silicon called the CZ (Czochralski) method.
- Crushed high-purity
polycrystalline silicon is doped with elements like arsenic, boron,
phosphorous or antimony and melted at 1400° in a quartz crucible
surrounded by an inert gas atmosphere of high-purity argon.
- The melt is
cooled to a precise temperature, then a "seed" of single crystal silicon
is placed into the melt and slowly rotated as it is "pulled" out. The
surface tension between the seed and the molten silicon causes a small
amount of the liquid to rise with the seed and cool into a single
crystalline ingot with the same orientation as the seed. The ingot
diameter is determined by a combination of temperature and extraction
speed.
- Crystals form when the
concentration of a solution is higher than the solubility of the
product. This of course is a thermodynamic process; however the
production of crystals is governed by kinetic mechanisms.
- This kinetic/
thermodynamic battle leads to a condition called supersaturation, a
condition where the concentration of the solution is higher than the
solubility product but where crystals have not been produced.
- Crystals find numerous
applications in research and modern technology.
- Knowledge of
crystal properties and of their magnitude is the determining factor in
their selection for a given purpose.
- In addition, measured
properties of a crystal are of theoretical interest. The mere existence
of a property provides information about crystal symmetry, while its
actual value allows comparison with theoretical values derived from a
microscopic or quantum-mechanical model.
- Photovoltaic modules
make up about two-thirds of the lowest achievable grid-connected system
prices that have been reported.
- In 2005 the
average price of modules in the reporting countries was around 4,5 USD
per watt, an increase of less than 5 % over the corresponding figure for
2004.
- Interestingly, a
number of countries reported a decrease in module prices from 2004 while
other countries reported almost no change.
- The widely discussed
increase in module prices appears to have been a largely European
phenomenon in 2005, possibly due to the local pressures on demand.
- Lascas1 mining and
processing in Arkansas was stopped at the end of 1997, and in 2005, no
U.S. firms reported the production of cultured quartz crystals.
- Cultured quartz crystal
production capacity still exists in the United States using imported and
stockpiled lascas as feed material.
- In the past
several years, cultured quartz crystal was increasingly produced
overseas, primarily in Asia.
- The native gallium
nitride(GaN) crystal is used for the development of ion sensors.
- The quartz crystal
microbalance (QCM) technique has been shown to play a key role in
elucidating various aspects of Biomacromolecular recognition
reactions.
- The adsorption of
radioactiveCs13 technique might be useful in detecting defective quartz
crystals without destructive testing.
- Electronic
applications accounted for most industrial uses of quartz crystal; other
uses included special optical applications.
- Crystal growth
processes provide basic materials for many applications and are for
example one key technology in the chain of all manufacturing processes
for electronic devices.
- The research and
development of crystal growth processes is driven by the demands which
come from the specific applications; but in common there is a need for
an increase of crystal dimensions, improved uniformity of the relevant
crystal properties in the micro- and macroscale and materials with new
properties.
- The production of
quartz frequency control crystals rated the second highest military
priority- second only to atomic energy.
- A Country is well-named
as the "land of crystals". With 70% of the national reserve of the
precious material, it produces 80% of China's crystal products.
- The Taiwanese market
for quartz crystals is generally dominated by Japanese
companies.
|
Natural Crystals
General Information
- Crystal
- Different Kinds of
Crystals
- Types of Crystals
- Physical Properties of
Crystal
- Crystal
structure
- Creating
Crystals
Company
- Company from
Newjersey
- Company from
Russia
- Company from
Canada
- Company from
China
- Company from British
Columbia
- Company from
Pakistan
Manufacturers and
Suppliers
- Aquamarine Crystal
Suppliers
- Calcite crystal
Suppliers
- Crystal Manufacturers
- Topaz Stone
Suppliers
- Trade Leads of
Crystals
- Wholesalers of
Crystal
- Rose Quartz Crystal
Suppliers
Products
- Crystal ball
- Natural Crystal
Deodarant
- Crystal pendant
- Saly crystal
lamps
- Natural crystal
bracelet
- Natural crystal product
list
- Natural crystals
Functions and
Properties
- Properties of Crystals
- Mechanisms of classical
crystal growth theory
- Crystal
Properties
- Magnetic Properties of
Crystal
Crystal Polishing
Procedures
- Polishing slide for the
crystals
- Plastic crystal
polishing
- Crystal and Rock
Polishing
- Polishing Glass Pocket
Watch Crystals Methods
- Polishing Crystal
Procedure
Buyers
- Foreign Buyers of
Crystals
- Importers of
Crystals
Project
- Crystal Giant
Project
- Growing crystals-
factors that affect the rate and the size - science Project
- Growing Crystal Science
Project
- Growing Crystals
Safety and
Guides
- Guide to Polishing Crystals
- Useful Links of
Crystal
Applications
- Frequency Behavior of a
Quartz Crystal Microbalance (Qcm) in Contact with Selected
Solutions
- Application in various
metrological problems
- Crystals in Biological
Applications
- Applications for
Crystals
- Magical Uses of
Crystals
- Crystals and their
Uses
- Uses of Crystals
Technology and
Techniques
- Development of Crystal
Growth Technology
- A
Crystal Collimation Experiment at the Tevatron
- Modern crystal
processing technology
-
- Crystal Growth
Techniques
- Crystallization
Techniques
Patent
- Process for producing
amethyst crystals
- Rod shaped apatite
crystals
- Method for producing
calcite-type calcium carbonate single crystal
- Method for diffracting
crystals
- Methods for controlling
crystal growth, crystallization, structures and phases in materials and
systems
- Method for the
preparation of single crystals of gadolinium gallium garnet
- Purified quartz and
process for purifying quartz
- Method for producing
crystals
Market
- Quartz Crystal Market
Demand
- Booming Crystal Market
- Devising a Crystal
Clear Future
- Jiangsu crystal market
shines brighter
- Market Information of
Quartz Crystal in Taiwan
- Market Information of
Quartz Crystal in South Korea
- Silicon and Crystal Timing Solutions Market
- Diamond polishing in
India
- Natural Stones
market
Report
- Crystal Growth
Laboratory Annual Report
- Report for
Crystal
- Silicon Crystal Growing
Facility
- Natural Crystal quartz
gold laser for healing
Cultured Crystals
General
Information
-
Synthetic
quartz crystals
-
Origin of authigenic inclusions in
synthetic crystals
-
Synthetic lightsaber crystal
-
Research on Synthetic
crystal
Production and
processing
- Production of quartz
crystal in 2005
- Production of quartz
crystal in 2006
- Production of quartz
crystal in 2001
- Production of quartz
crystal
- Production of quartz
crystal in 2004
- Production of quartz
crystal in 2007
- Modeling in Industrial
Silicon Wafer Manufacturing - From Crystal Growth to Device
Processes
- Manufacturing Process
of Cavan Crystal
- Manufacturing Process
of Crystal
- Silicon Crystal Growth
and Wafer Production
- Multiscale simulations
of industrial crystal growth
Products
- Crystal Products
- Crystal Shree
- Crystal Decorative
Products
- Monolithic Crystal
Filter
- List of Crystal
Products
- Hand - cut beverage
glasses
- Crystal
Ornaments
- Surface Mount Tuning
Fork Quartz Crystal
|
Cultured Crystals
Crystal
Growth
- Crystal Growth of
Optical Materials for Advanced Lasers
- Growth of Mercuric
Iodide Crystals
- Growth features of
ammonium hydrogen d-tartrate single crystals
- Crystal growth and the
steady-state grain size during
high-energy ball-milling
- Crystal Growing
Bench
- Growth of Large KDP
Crystals in the Form of Plates
- Protein Crystal
Growth
- Modeling Snow Crystal
Growth
- Single crystal growth
of rare earth titanate pyrochlores
- Growth of
Crystal
Manufacturers and
Suppliers
- Canada Suppliers of
Crystal
- China Manufacturers of
Crystals
- Crystal
Encounters
- Engraved Glass and
Crystal Wholesale Supplier
- Crystal Abrasives
Manufacturers
Functions and
Properties
- Liquid crystal
properties
- Properties of single
crystal
- Unmeasured crystal
properties
- Quartz Crystal
Properties
Consultant
- Consultant from
Deutsche
- Consultant from
California
- Consultant from
London
- International
Consultant
Equipments
Suppliers
- Crystal acid
polishing machine Suppliers
- Crystal Cutting Machine
Suppliers
- Furnace Tube
Suppliers
- Manufacturers of
Heaters
- Crystal Polishing
Machine Manufacturers
- Suppliers of Vibratory
Feeder
Project
- Processes for Growing
Large, Single-Crystal Aluminum Nitride
- Light propagation in
photonic crystals
- Liquid Crystal Project
- New Liquid Crystal
Smart Window and its Production Process
- Surfaces and interfaces
of liquid crystals
Safety and
Guides
- Guidelines for TRS Single Crystal Based Stacked
Actuators
- Guidelines for Laser Safety and Hazard
Assessment
Applications
- Organic Crystals for
THz Wave Applications
- Application of a Liquid
Crystal Tunable Filter to Near-Infrared Spectral Searches
- Development of Single
Crystal Fibers for Optical, Scintillation and Mechanical
Applications
- Light shutters from
antiferroelectric liquid crystals of bent-shaped molecules
- Compact and portable
holographic camera using photorefractive crystals.
- Gallium Nitride-Based
Chemical Sensors
- Crystals Used for the
Production of Cubic Zirconia
- Liquid Crystals-
Applications and Uses
- Laser Crystals
Applications
- Modification of
Hydroxyapatite Crystal Using IR Laser
Technology and
Techniques
- Determination of
coupled solvent mass in quartz crystal microbalance measurements using
deuterated solvents
- Surface adsorption of
CS on Quartz crystals
- Piezo printing
technology
- Manufacture the Next
Generation Liquid Crystal Display (LCD) Chips
- CERN Technology
Transfer
- Fujitsu Develops
Efficient Silicon-Crystal Production
Technology
- Smith and Cartz Crystal
Growth Techniques
Material
Safety Data Sheet
- Bismuth Germanate
Crystal
- Pine Crystal Bowlene
Toilet Bowl Cleaner
- Cadmium Tungstate
Scintillation Crystal
- Diamond
Crystal
- Quartz Crystal MSDS
- Ink Crystal Stamp
Pads
- Thallium Bromide
Optical Crystal
Market
- Trends in Photovoltaic
Applications Survey
- Market for Quartz
Piezoelectric Crystal
- Markets Expand for
Piezoelectric Ceramics
- Market for Swarovski's
crystal
Report
- Single Crystal
Piezocomposite Transducer Materials
- Multiple Time Scale
Simulations of Metal Crystal Growth
- Silicon Float-Zone
Crystal Growth
- Survey report of
selected IEA countries about Photovoltaic Application
- Controlling crystal
evolution on the nanosca
Order the CD ROM
Today |