File Pyrosensor.jpg thumb Pyroelectric sensor Pyroelectricity from the Greek pyr , fire, and electricity is the ability of certain materials to generate a temporary voltage when they are heated or cooled. ref name Webster The change in temperature modifies the positions of the atoms slightly within the crystal structure , such that the polarization electrostatics polarization of the material changes. This polarization change gives rise to a voltage across the crystal. If the temperature stays constant at its new value, the pyroelectric voltage gradually disappears due to Leakage electronics leakage current the leakage can be due to electrons moving through the crystal, ions moving through the air, current leaking through a voltmeter attached across the crystal, etc. . ref name Webster cite ... Pyroelectricity should not be confused with thermoelectricity In a typical demonstration of pyroelectricity ... voltage across the crystal. Explanation Pyroelectricity can be visualized as one side of a triangle ... not allow pyroelectricity. Very small changes in temperature can produce an electric potential due to a materials pyroelectricity. Passive infrared sensor s are often designed around pyroelectric materials ... the attractive properties of the mineral when heated. Pyroelectricity was first described&mdash although ... needed date January 2012 Research in pyroelectricity became more sophisticated in the 19th century. In 1824 ... develop a theory for the processes behind pyroelectricity. Pierre Curie and his brother, Jacques Curie , studied pyroelectricity in the 1880s, leading to their discovery of some of the mechanisms ... cell, and exhibit pyroelectricity. If this dipole can be reversed by the application of an electric ..., 3m, 6, 6, 622, 6mm, 62m, 23, 43m Pyroelectric 1, 2, m, mm2, 3, 3m, 4, 4mm, 6, 6mm The property of pyroelectricity ... probe force microscope References reflist Lang, Sidney B., 2005, Pyroelectricity From Ancient Curiosity ... Pyroelectric Infrared Detectors DIAS Infrared http www.doitpoms.ac.uk tlplib pyroelectricity index.php ... more details
with lithium tantalate http www.physicstoday.org vol 58 iss 8 p31.html Pyroelectricity From Ancient ... SrBaNb2O6 See also Lithium tantalate Zinc oxide Pyroelectric fusion Pyroelectricity DEFAULTSORT ... more details
Refimprove date December 2009 Paul Jacques Curie October 29, 1856 &ndash 1941 was a France French physicist and professor at the University of Montpellier . He and his brother, Pierre Curie , studied pyroelectricity in the 1880s, leading to their discovery of some of the mechanisms behind piezoelectricity . ref cite journal author Manbachi, A. and Cobbold R.S.C. title Development and Application of Piezoelectric Materials for Ultrasound Generation and Detection journal Ultrasound volume 19 issue 4 pages 187 196 year 2011 month November doi 10.1258 ult.2011.011027 url http ult.rsmjournals.com content 19 4 187.full ref Reflist Persondata Metadata see Wikipedia Persondata . NAME Curie, Jacques ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH October 29, 1856 PLACE OF BIRTH DATE OF DEATH 1941 PLACE OF DEATH DEFAULTSORT Curie, Jacques Category French physicists Category 1856 births Category 1941 deaths france physicist stub de Jacques Curie es Jacques Curie fr Jacques Curie it Jacques Curie ja pt Jacques Curie ru , zh ... more details
For the mineral, see Wurtzite unreferenced date January 2012 Image Wurtzite kassebaum.gif thumb right 150px Wurtzite structure Image Wurtzite unit cell 3D balls.png thumb right 150px Wurtzite unit cell Image Wurtzite polyhedra.png thumb 150px right Wurtzite structure image Hexagonal lattice.svg thumb 150px right General hexagonal crystal structure The wurtzite crystal structure , named after the mineral wurtzite , is a crystal structure for various binary compound s. It is an example of a hexagonal crystal system . Among the compounds that can take the wurtzite structure are wurtzite itself, Silver iodide AgI , Zinc oxide ZnO , Cadmium sulfide CdS , Cadmium selenide CdSe , Silicon carbide SiC , Gallium III nitride GaN , Aluminium nitride AlN , and other semiconductors. In most of these compounds, wurtzite is not the favored form of the bulk crystal, but the structure can be favored in some nanocrystal forms of the material. In materials with more than one crystal structure, the prefix w is sometimes added to the empirical formula to denote the wurtzite crystal structure, as in w BN . Each of the two individual atom types forms a sublattice which is close packing HCP type short for hexagonal close pack . When viewed altogether, the atomic positions are the same as in lonsdaleite hexagonal diamond . Each atom is tetrahedrally coordinated. The wurtzite structure is centrosymmetry non centrosymmetric i.e., lacks inversion symmetry . Due to this, wurtzite crystals can and generally do have properties such as piezoelectricity and pyroelectricity , which centrosymmetric crystals lack. fact date January 2012 External links http cst www.nrl.navy.mil lattice struk b4.html The Wurtzite structure Category Crystallography fa ... more details
exploration industry. The process of pyroelectricity has been known from ancient times ... targets. See also Neutron source s Neutron generator Pyroelectricity Pyroelectric crystal Notes reflist References Sidney Lang, http www.slac.stanford.edu grp arb tn arbvol5 AARD459.pdf Pyroelectricity ... B. Lang, Sourcebook of Pyroelectricity , London Gordon & Breach, 1974 V. D. Dougar Jabon, G. V. Fedorovich ... more details
Infobox mineral name Axinite category Borosilicates boxwidth 180px image Axinite Oisan.jpg caption Axinite Deposit Topotype, France formula Ca,Fe,Mn sub 3 sub Al sub 2 sub BO sub 3 sub Si sub 4 sub O sub 12 sub OH or Ca sub 2 sub Fe,Mn Al sub 2 sub BSi sub 4 sub O sub 15 sub OH color Reddish brown to yellow to colorless. Blue, violet, grey. habit Tabular, wedge shaped crystals system Triclinic cleavage Good on 100 fracture Conchoidal mohs 6.0 7.5 luster Vitreous refractive n sub sub 1.672 1.693 br n sub sub 1.677 1.701 br n sub sub 1.681 1.704 opticalprop Biaxial birefringence 0.011 pleochroism Strong streak White gravity 3.18 3.37 melt fusibility solubility other references ref name Galleries http mineral.galleries.com Minerals Silicate AXINITE AXINITE.htm Axinite . Mineral Galleries ref ref http www.mindat.org min 440.html Axinite . Mindat ref Axinite is a brown to violet brown, or reddish brown bladed group of mineral s composed of calcium aluminium boron boro silicon silicate , Ca,Fe,Mn sub 3 sub Al sub 2 sub BO sub 3 sub Si sub 4 sub O sub 12 sub OH. Axinite is pyroelectricity pyroelectric and piezoelectric . The axinite group includes ref name Galleries Axinite Fe , ferro axinite, iron rich, lilac brown to black Axinite Mg , magnesio axinite, magnesium rich, pale blue to gray Axinite Mn , manganaxinite, manganese rich, yellow orange Tinzenite, iron manganese intermediate, yellow Gallery gallery File Axinite 64246.jpg Clove brown axinite crystals to 2.3 cm set atop matrix from the West Bor Pit at Dalnegorsk, Russia File Axinite 60191.jpg Chloritized bladed crystals of Axinite forming on Adularia from the Swiss Alps gallery References commons category Axinite Reflist Manganese minerals Category Calcium minerals Category Iron minerals Category Manganese minerals Category Aluminium minerals Category Sorosilicates Category Triclinic minerals silicate mineral stub ar be de Axinit et Aksiniit es Axinita eo Aksinito fa fr Axinite he ... more details
class infobox style width 25em align center bgcolor 9966FF colspan 2 align center GaPO sub 4 sub align center colspan 2 Image GaPO4 crystal.jpg 270px GaPO4 crystal align center bgcolor 9966FF colspan 2 General Category crystal Chemical formula or Chemical composition Composition GaPO sub 4 sub align center bgcolor 9966FF colspan 2 Identification Color Clear Crystal system Hexagonal crystal system Trigonal Crystal class 32 or D sub 3 sub Sch nflies notation Sch nflies Cleavage crystal Cleavage None Fracture Conchoidal Mohs Scale hardness 5.5 Refractive index n sub o sub 1.605, n sub e sub 1.623 Pleochroism None Streak mineralogy Streak White Density 3570 kg m sup 3 sup Solubility insoluble in pH 5 8 align center bgcolor 9966FF colspan 2 other properties pyroelectric crystal Pyroelectricity None Particular characteristics quartz isotype , piezoelectricity piezoelectric effect up to 950 C 1742 F Gallium phosphate GaPO sub 4 sub or gallium orthophosphate is a colorless trigonal crystal with a hardness of 5.5 on the Mohs scale . GaPO sub 4 sub is isotypic with quartz , possessing very similar properties, but the silicon atoms are alternately substituted with gallium and phosphorus , thereby doubling the piezoelectricity piezoelectric effect . GaPO sub 4 sub has many advantages over quartz for technical applications, like a higher electromechanical coupling coefficient in crystal oscillator resonators , due to this doubling. Contrary to quartz, GaPO sub 4 sub is not found in nature. Therefore, a hydrothermal process must be used to synthesize the crystal. Modifications GaPO sub 4 sub possesses, in contrast to quartz, no phase transition , thus the low temperature structure structure like quartz of GaPO sub 4 sub is stable up to 970 C, as are most of its other physical properties. Around 970 C another phase transition occurs which changes the low quartz structure into another structure similar with cristobalite . Structure The specific structure of GaPO sub 4 sub sho ... more details
, and pyroelectricity make ferroelectric capacitors very useful, e.g. for sensor applications ... of a material in response to a change in temperature is called pyroelectricity . Ferroelectric ... Piezoelectricity Pyroelectricity Antiferroelectricity Ferroelasticity Flexoelectricity Condensed matter ... more details
Chembox ImageFile Triglycine sulfate.svg commented out pending reading of the literature. Glycine will be protonated at pH 1.5. ImageSize 200px IUPACName Glycine sulfate 3 1 OtherNames Glycine sulfate TGS Section1 Chembox Identifiers CASNo 513 29 1 CASNo Ref cascite correct CAS PubChem 10551 ChemSpiderID 10111 SMILES O C O CN.O S O O O.O C O CN.O C O CN InChI InChI 1S 3C2H5NO2.H2O4S c3 3 1 2 4 5 1 5 2,3 4 h3 1,3H2, H,4,5 H2,1,2,3,4 Section2 Chembox Properties C 6 H 17 N 3 O 10 S 1 Appearance White powder Density 1.69 g cm sup 3 sup ref cite book author Kwan Chi Kao title Dielectric phenomena in solids with emphasis on physical concepts of electronic processes url http books.google.com books?id 53iDBqayjMYC&pg PA318 accessdate 12 May 2011 year 2004 publisher Academic Press isbn 9780123965615 pages 318 ref MeltingPt BoilingPt Solubility Section3 Chembox Structure CrystalStruct Monoclinic SpaceGroup P2 sub 1 sub ref name j1 LattConst a 0.9417 nm LattConst b 1.2643 nm LattConst c 0.5735 nm LattConst beta 110 Coordination Section7 Chembox Hazards MainHazards FlashPt Autoignition Triglycine sulfate TGS is a chemical compound with a formula NH sub 2 sub CH sub 2 sub COOH sub 3 sub H sub 2 sub SO sub 4 sub . The empirical formula of TGS does not represent the molecular structure, which contains protonated glycine moieties and sulfate ions. TGS with protons replaced by deuterium is called deuterated TGS or DTGS alternatively, DTGS may refer to doped TGS. TGS and DTGS crystals are Pyroelectricity pyroelectric and Ferroelectricity ferroelectric and have been used as detector elements in infrared spectroscopy . Crystal structure and properties File TGSstructure.png thumb left Crystal structure of TGS. Hydrogen atoms are not shown. ref name j1 cite journal doi 10.1039 A907937H title Water assisted reconstruction on ferroelectric domain ends of triglycine sulfate NH sub 2 sub CH sub 2 sub COOH sub 3 sub H sub 2 sub SO sub 4 sub crystals author Subramanian Bala ... more details
of a solvent on a crystal face, and indicate its true symmetry and the Pyroelectricity pyroelectric ... twins producing V shaped or fishtail terminations. Scolecite is Pyroelectricity pyroelectric and Piezoelectricity ... more details
. This propelled a number of developing applications on piezoelectricity and pyroelectricity ... See also Polyvinylidene fluoride Ferroelectricity Piezoelectricity Pyroelectricity References references ... more details
pyroelectricity , and all pyroelectric materials are also piezoelectric. These materials can be used .... In turn, pyroelectricity is seen most strongly in materials which also display the ferroelectric ... field. Pyroelectricity is also a necessary consequence of ferroelectricity. This can be used to store ... more details
and early research The pyroelectricity pyroelectric effect , by which a material generates an electric ... Pierre Curie and Jacques Curie . They combined their knowledge of pyroelectricity with their understanding of the underlying crystal structures that gave rise to pyroelectricity to predict crystal ... due to a non vanishing electric dipole moment associated with their unit cell, and which exhibit pyroelectricity ... more details
A Passive Infrared sensor PIR sensor is an electronic device that measures infrared IR light radiating from objects in its field of view. PIR sensors are often used in the construction of PIR based motion detector s see below . Apparent motion is detected when an infrared source with one temperature , such as a human , passes in front of an infrared source with another temperature, such as a wall . This is not to say that the sensor detects the heat from the object passing in front of it but that the object breaks the field which the sensor has determined as the normal state. Any object, even one exactly the same temperature as the surrounding objects will cause the PIR to activate if it moves in the field of the sensors. ref http www.gadgetshack.com motionsensor.html PIR Motion Sensor page of http www.gadgetshack.com GadgetShack.com . ref All objects above absolute zero emit energy in the form of radiation. Usually infrared radiation is invisible to the human eye but can be detected by electronic devices designed for such a purpose. The term passive in this instance means that the PIR device does not emit an infrared beam but merely passively accepts incoming infrared radiation. Infra meaning below our ability to detect it visually, and Red because this color represents the lowest energy level that our eyes can sense before it becomes invisible. Thus, infrared means below the energy level of the color red, and applies to many sources of invisible energy. ref cite web url http steveslockandsafe.com venice locksmith home security technicians notebook title Venice Locksmith Home Alarm PIR Tech & 124 Steve s Lock & Safe publisher Steveslockandsafe.com date 2010 03 19 accessdate 2011 12 06 ref Design Infrared radiation enters through the front of the sensor, known as the sensor face . At the core of a PIR sensor is a Solid state electronics solid state sensor or set of sensors, made from an approximately 1 4 inch square of natural or artificial pyroelectricity pyroelect ... more details
File KustodiyevSemenov Kapitsa.JPG thumb 220px Physicist Pyotr Kapitsa left and physical chemist Nikolay Semyonov right , the two Nobel laureate s portrait by Boris Kustodiev , 1921 . This list of Russia n physicist s includes the famous physicists from the Russian Empire , the Soviet Union and the Russian Federation . Expand list date February 2011 Alphabetical list compactTOC8 side yes seealso yes NOTOC A Alexei Alexeyevich Abrikosov Alexei Abrikosov , discovered how magnetic flux can penetrate a superconductor the Abrikosov vortex , Nobel Prize winner Franz Aepinus , related electricity and magnetism , proved the electric nature of pyroelectricity , explained electric polarization and electrostatic induction , invented Achromatic lens achromatic microscope Zhores Alferov , inventor of modern heterotransistor , Nobel Prize winner Artem Alikhanian , a prominent researcher of cosmic rays , inventor of wide gap track spark chamber Abraham Alikhanov , a prominent researcher of cosmic rays , built the first nuclear reactor s in the USSR Semen Altshuler , researched Electron paramagnetic resonance EPR and NMR , predicted acoustic paramagnetic resonance Lev Artsimovich , builder of the first tokamak , researcher of high temperature Plasma physics plasma Gurgen Askaryan , predicted self focusing of light, discovered Askaryan effect in the particle physics File Zhores Alferov.jpg thumb 95px Zhores Alferov Alferov B Nikolay Basov , physicist, co inventor of laser and maser , Nobel Prize winner Nikolay Bogolyubov , mathematician and theoretical physicist,co developed the BBGKY hierarchy , formulated a microscopic theory of superconductivity , suggested a triplet quark model, introduced a new quantum degree of freedom color charge Gersh Budker , inventor of electron cooling , co inventor of collider C Sergey Chaplygin , a founder of aerodynamics aero and hydrodynamics , formulated the Chaplygin s equation s and Chaplygin gas concept Pavel Cherenkov , discoverer of Cherenkov r ... more details
to its Pyroelectricity pyroelectric properties or according to other sources mixed gemstones . Dravite ... exhausted. All hemimorphic crystals are Piezoelectricity piezoelectric , and are often pyroelectricity ... more details
detectors mainly used for IR , pyroelectricity pyroelectric detectors, and microbolometer ... links for links to phosphor information. Pyroelectricity Pyroelectric detectors respond to changes ... more details
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