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Topic: Crystalline lattice

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	Thermoluminescence dating - Wikipedia, the free encyclopedia
		Natural crystalline materials contain imperfections-impurity ions, stress dislocations, and other phenomena that disturb the regularity of the electric field that holds the atoms in the crystalline lattice together.
		When such irradiated crystalline material is heated or exposed to strong light, the trapped electrons are given sufficient energy to escape from the traps.
		In the process of recombining with a lattice ion, an electron loses energy and a photon (a light quantum) is emitted, detectable in the laboratory.
	en.wikipedia.org /wiki/Thermoluminescence_dating (687 words)

	W0376: Structure Analysis of Reaction Intermediates Trapped in Crystalline Lattice (Site not responding. Last check: 2007-10-21)
		However, the unstable species produced by photo irradiation may be trapped in the crystalline lattice at low temperatures and the structures can be analyzed by X-ray technique.
		The crystal structure after irradiation indicated that a dinitrogen molecule and the hexachlorodiphenylcarbene were produced in the crystalline lattice.
		The structure after irradiation revealed that the molecule is changed to a dinitrogen molecule and a 2-biphenylnitrene due to the cleavage of the azido group.
	www.hwi.buffalo.edu /ACA/ACA01/abstracts/text/W0376.html (254 words)

	Wigner-Seitz cell - Wikipedia, the free encyclopedia
		In solid state physics, a Wigner-Seitz cell is a primitive lattice cell of a crystalline lattice.
		In the case of a three-dimensional lattice, a perpendicular plane is drawn at the midpoint of the lines between the lattice points.
		The primitive cell in the reciprocal lattice in momentum space is called the Brillouin zone.
	en.wikipedia.org /wiki/Wigner-Seitz_cell (198 words)

	Introduction to Cubic Crystal Lattice Structures (Site not responding. Last check: 2007-10-21)
		The outstanding macroscopic properties of crystalline solids are rigidity, incompressibility and characteristic shape.
		All crystalline solids are composed of orderly arrangements of atoms, ions, or molecules.
		The macroscopic result of the microscopic arrangements of the atoms, ions or molecules is exhibited in the symmetrical shapes of the crystalline solids.
	www.okstate.edu /jgelder/solstate.html (538 words)

	Phonon - Wikipedia, the free encyclopedia
		A phonon is a quantized mode of vibration occurring in a rigid crystal lattice, such as the atomic lattice of a solid.
		If the lattice is rigid, the atoms must be exerting forces on one another, so as to keep each atom near its equilibrium position.
		According to thermodynamics, when the lattice is held at a non-zero temperature its energy is not constant, but fluctuates randomly about some mean value.
	en.wikipedia.org /wiki/Phonon (2152 words)

	Dave Jewitt: Kuiper Belt: Latest Research
		Crystalline ice, in which the water molecules are arranged in a regular lattice-like pattern, indicates formation at temperatures in excess of 110 K (about -160 C).
		The extra wrinkle is that crystalline ice, however it came to be emplaced on the surface of Quaoar, is itself unstable.
		Bombardment by energetic particles from the solar wind and by cosmic rays breaks the bonds between molecules in the crystalline lattice producing amorphous ice.
	www.ifa.hawaii.edu /faculty/jewitt/quaoar.html (649 words)

	Olympus Microscopy Resource Center: Light and Color - Optical Birefringence
		The simplest crystalline lattice structure is cubic, as illustrated by the molecular model of sodium chloride in Figure 1(a), in which all of the sodium and chloride ions are arranged with uniform spacing along three mutually perpendicular axes.
		The lattice structure illustrated in Figure 1(b) represents the mineral calcite (calcium carbonate), which consists of calcium and carbonate ions.
		Anisotropic crystals, on the other hand, have crystallographically distinct axes and interact with light in a manner that is dependent upon the orientation of the crystalline lattice with respect to the incident light.
	www.olympusmicro.com /primer/lightandcolor/birefringence.html (2366 words)

	Olympus Microscopy Resource Center: Light and Color - Optical Birefringence
		The simplest crystalline lattice structure is cubic, as illustrated by the molecular model of sodium chloride in Figure 1(a), an arrangement where all of the sodium and chloride ions are ordered with uniform spacing along three mutually perpendicular axes.
		Anisotropic crystals, such as quartz, calcite, and tourmaline, have crystallographically distinct axes and interact with light by a mechanism that is dependent upon the orientation of the crystalline lattice with respect to the incident light angle.
		Transparent crystalline materials are generally classified into two categories defined by the number of optical axes present in the molecular lattices.
	www.olympusmicro.com /primer/lightandcolor/birefringenceintro.html (4733 words)

	United States Patent Application: 0030213950
		The thin film layer's lattice constant is adjusted either during epi growth to accommodate the different lattice constant of the target epi layers; or is adjusted prior to the epi growth to create a thin film layer lattice-matched to the target material system.
		Preferably, the lattice constant of thin adaptive layer 22 is modified to match the lattice constant of the material system of epi layer 24 which is to be grown thereon.
		This is because, in the prior art, a substrate had to be utilized which is lattice matched to the epi layers, which often limited the choice to materials that were opaque to the pumping light from pump laser 130.
	appft1.uspto.gov /netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=/netahtml/PTO/srchnum.html&r=1&f=G&l=50&s1="20030213950".PGNR.&OS=DN/20030213950&RS=DN/20030213950 (7088 words)

	Text of MIJ-NSR Volume 3, Article 16 (Site not responding. Last check: 2007-10-21)
		For example, the lattice constant mismatch between GaN and AlN is 2.5% and 4.1% for a and c constants respectively; the mismatch between GaN and InN is much greater -10.7% and 15.0% ; for the pair InN and AlN the lattice constant mismatch approaches 13.6% and 19.7% for a and c constants [1].
		This approach is found to give the results very close to those obtained by the elaborated model [8] accounting for relaxation of the crystalline lattice of ternary compound in several coordination shells.
		N layers of wurtzite crystalline structure having the interface oriented parallel to hexagonal axis of the crystal.
	nsr.mij.mrs.org /3/16/text.html (1945 words)

	crystal -> Classification of Crystals on Encyclopedia.com 2002
		The positions form a kind of scaffolding, called a crystalline lattice; the atomic occupancies of lattice positions are determined by the chemical composition of the substance.
		A crystalline substance is uniquely defined by the combination of its chemistry and the structural arrangement of its atoms.
		Crystalline substances are grouped, according to the type of symmetry they display, into 32 classes.
	www.encyclopedia.com /html/section/crystal_classificationofcrystals.asp (669 words)

	Phonon (Site not responding. Last check: 2007-10-21)
		The study of phonons is an important part of solid state physics, because they contribute to many of the physical properties of materials, such as thermal and electrical conductivity.
		According to a well-known result in classical mechanics, any vibration of a lattice can be decomposed into a superposition of normal modes of vibration.
		The speed of propagation of a phonon, which is also the speed of sound in the lattice, is given by the slope of the dispersion relation, ∂ω
	www.sciencedaily.com /encyclopedia/phonon (2093 words)

	Crystal Lattice Structures
		This lattice is "closest packed", because spheres of equal size occupy the maximum amount of space in this arrangment (74.05%); since this closest packing is based on a cubic array, it is called "cubic closest packing": CCP = FCC.
		Rhombohedral (R) lattice - If, in the (ABC) layered lattice, the interplanar spacing is not the closest packed value (1.633r), then the primitive (Z = 1) unit cell is a rhombohedron with a = b = c <> 2r and alpha = beta = gamma <> 60 degrees.
		Zinc Blende lattices - The lattice of cations in zinc blende is a FCC lattice of the same dimension as the anion lattice, so the structure can be described as interpenetrating FCC lattices of the same unit cell dimension.
	www.chem.lsu.edu /htdocs/people/sfwatkins/ch4570/lattices/lattice.html (1147 words)

	Thermally Oxidized Silicon
		The specific oxidation method used has an effect on the amount of expansion of the silicon lattice, so the peak position is not always at 0.45, but is close to it.
		An asymmetry observed in the peak is due to a smaller lattice expansion near the interface than in the bulk of the oxide.
		Although the scattering is different for each crystal orientation because the expansion is along a different crystallographic direction, in every case, the silicon atoms in the oxide have a "memory" of the original crystalline structure.
	www-ssrl.slac.stanford.edu /research/highlights_archive/oxidizedsi.html (867 words)

	Integrated circuit substrate that accommodates lattice mismatch stress - US Patent 6429466 (Site not responding. Last check: 2007-10-21)
		A method for growing a crystalline layer that includes a first material on a growth surface of a crystalline substrate of a second material, wherein the first material and the second material have different lattice constants.
		The isolated layer of the substrate has a thickness that is less than the thickness at which defects are caused in the crystalline lattice of the first material by the second material crystallizing thereon.
		The buried layer is sufficiently malleable at the growth temperature to allow the deformation of the lattice of the isolated layer without deforming the remainder of the substrate.
	www.patentstorm.us /patents/6429466.html (325 words)

	The structure of metal (Site not responding. Last check: 2007-10-21)
		Grain boundaries aside, each grain in a pure metal has the same crystalline structure as any other grain, assuming the temperature is the same.
		For our purposes, all metals and alloys are crystalline solids, although some metals have been formed in the lab without crystalline structure.
		And for the record, yes, there are substances without crystalline structure at room temperature; for example, glass and silicone.
	www.thefabricator.com /Articles/Welding_Article.cfm?ID=568 (1251 words)

	Reshaping of Single Crystalline Silicon Microstructures (Site not responding. Last check: 2007-10-21)
		This paper reports on the thermal plastic deformation of single crystalline silicon(SCS) microstructures due to Joule heating generated by a current passing through the structures.
		It is known that SCS is plastically deformed at a temperature higher than 650, which is done at elevated temperature for a long time, different from the plastic deformation by Joule heating.
		When the Joule heating is started, the crystalline lattice is disturbed at the buckled point.
	www.fujita3.iis.u-tokyo.ac.jp /research/1997/yang.html (587 words)

	Sören Bartels' Home Page
		When certain crystalline solids undergo a change in temperature one can observe a structural change in the crystalline lattice.
		For instance, an arrangement of atoms in a highly structured lattice consisting of cubes may change into a tetragonal phase with less symmetry.
		It has been shown by Ball & James and Kinderlehrer & Luskin that an efficient description of crystalline microstructure can be obtained by extending the space of admissible deformations to certain measure-valued functions which allow for a local statistical description of oscillations on arbitrarily fine scales.
	www.math.umd.edu /~sba/phase_trans/phase_trans.html (909 words)

	Notebook
		The positions form a kind of scaffolding, called a crystalline lattice; the atomic occupancies of lattice positions re determined by the chemical composition of the substance.
		The formation of a crystal by a substance passing from a gas or liquid to a solid state, or by going out of solution (by precipitation or evaporation), is called crystallization.
		For example, crystalline substances that have special electrical properties are much used in communications equipment.
	www.noteaccess.com /MATERIALS/Ceramics/Clay.htm (2537 words)

	Chapter 1: Spin Models
		In 1944 the physicist Lars Onsager, studying the 2-dimensional Ising model on a square lattice, was able to demonstrate by analytical means the existence of a phase transition in the model, a result considered to be a landmark in the physics of critical phenomena.
		The analogue of this in three dimensions is the "cubic" lattice, and 4- and higher-dimensional analogues are known as "hypercubic" lattices.
		In most studies a spin system includes a lattice in which all sites are occupied by spins and in which all lattice bonds are interpreted as energetic bonds (i.e., associated with that bond is an energy which contributes to the total energy of the system).
	www.hermetic.ch /compsci/thesis/chap1.htm (6408 words)

	[No title] (Site not responding. Last check: 2007-10-21)
		But it really never proved viable, due to problems with the mismatch between the silicon and GaAs crystalline lattice, which caused a significant number of dislocation defects at the interface of the two materials, extending into the active area of the devices.
		While working with strontium titanate, a material with a high dielectric constant (high k) that has applications as a gate dielectric and for DRAM capacitors, researchers noted that the lattice size of the material was such that it might make a good buffer material.
		He knew the lattice match would be pretty good to strontium titanate and, in fact, the second time he attempted to grow it, it was indeed successful." That was a little less than two years ago.
	www.reed-electronics.com /semiconductor/index.asp?layout=articlePrint&articleID=CA163925 (623 words)

	Colloidal Crystals Made of Polystyrene Spheroids: Fabrication and Structural/Optical Characterization
		Such a crystalline lattice was fabricated by infiltrating an opaline lattice of monodispersed polystyrene spheres with an elastomer precursor such as poly(dimethylsiloxane) (or PDMS), followed by thermal curing and stretching of the composite film at a temperature higher than the glass transition temperature of polystyrene.
		The position of this stop band was determined by the diameter of the polystyrene spheres and the elongation ratio of the elastomeric composite.
		When the crystalline lattice was made of 240-nm polystyrene spheres, the stop band shifted from 594 to 522 nm, as the PDMS film was stretched by an elongation of 130%, and further down to 470 nm, as the incident angle was changed from 0 to 45
	pubs.acs.org /cgi-bin/abstract.cgi/langd5/2002/18/i20/abs/la025946w.html (300 words)

	OLYMPUS MIC-D: Physics of Light and Color - Optical Birefringence (Site not responding. Last check: 2007-10-21)
		This equation was derived for specific frequencies of light and ignores dispersion of light as it passes through the material.
		Transparent crystalline materials are generally classified into two categories defined by the number of optical axes present in the lattices.
		Structural birefringence is a term that applies to a wide spectrum of anisotropic assemblies including biological macromolecular assemblies such as chromosomes, muscle fibers, microtubules, liquid crystalline DNA, and fibrous protein structures such as hair.
	www.mic-d.com /curriculum/lightandcolor/birefringence.html (4593 words)

	AllRefer.com - X-ray crystallography, Mineral (Mineralogy And Crystallography) - Encyclopedia
		When an X-ray beam bombards a crystalline lattice in a given orientation, the beam is scattered in a definite manner characterized by the atomic structure of the lattice.
		This phenomenon, known as X-ray diffraction, occurs when the wavelength of X-rays and the interatomic distances in the lattice have the same order of magnitude.
		A year later Lawrence Bragg successfully analyzed the crystalline structures of potassium chloride and sodium chloride using X-ray crystallography, and developed a rudimentary treatment for X-ray/crystal interaction (Bragg's Law).
	reference.allrefer.com /encyclopedia/X/Xraycrys.html (336 words)

	Science NewsBriefs (Site not responding. Last check: 2007-10-21)
		Current methods for using transmission electron microscopes (TEMs) to image materials typically can't distinguish objects smaller than 0.15 nanometers, including the individual columns of atoms in a crystalline lattice.
		Individual atomic columns in a crystalline lattice can therefore only be imaged for a few low-order orientations, limiting the range of defects that can be imaged at atomic resolution.
		We present direct images from an aberration-corrected scanning TEM that resolve a lattice in which the atomic columns are sepa-rated by less than 0.1 nanometer.
	www.world-science.net /ScienceNewsBriefs/stories/040917_crystal.htm (259 words)

	[No title] (Site not responding. Last check: 2007-10-21)
		The lattice constant of Ge at room temperature is a = 5.65 Å.
		A crystalline lattice is characterized by the cubic unit cell pictured below.
		Determine the number of atoms per cm3 in the crystal if the lattice constant a is 0.5 nm.
	www.rpi.edu /~gessmt/activities/Class-activity-01.doc (253 words)

	[No title] (Site not responding. Last check: 2007-10-21)
		Ge crystallizes in diamond lattice structure, which means there are 8 atoms in one unit cell.
		Since the lattice constant is 5.65 × 10-8cm, we can calculate the volume occupied by these 8 Ge atoms or we can calculate the number of Ge atoms in 1 cm3 of the Ge crystal.
		Imagine that the unit cell is repeated; this ends up in a SC lattice (and not in the bcc structure!) Determine the number of atoms per cm3 in the crystal if the lattice constant a is 0.5 nm.
	www.rpi.edu /~gessmt/activities/Activity1_new.doc (899 words)

	C&EN: LATEST NEWS - DOPING AT THE NANOSCALE
		Muller notes that the growth kinetics of the process prevent the oxygen atoms in the undoped layers from diffusing into the vacancies of the doped layers.
		When there's an oxygen vacancy in the crystalline lattice, he explains, the remaining atoms will lean this way and that, adjusting to take up some of the extra space.
		As they do, the atoms move out of their crystalline alignment and put strain on the lattice.
	pubs.acs.org /cen/news/8232/8232notw1.html (524 words)

	A LARGE SCALE QUASI-CRYSTALLINE LAMELLAR LATTICE IN CHLOROPLASTS OF THE GREEN ALGA ZYGNEMA -- Mclean and Pessoney 45 ...
		A LARGE SCALE QUASI-CRYSTALLINE LAMELLAR LATTICE IN CHLOROPLASTS OF THE GREEN ALGA ZYGNEMA -- Mclean and Pessoney 45 (3): 522 -- The Journal of Cell Biology
		A quasi-crystalline lamellar lattice was observed in chloroplasts
		The lattice is composed of one or two
	www.jcb.org /cgi/content/abstract/45/3/522 (197 words)

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