2. A crystalline substance that has semiconducting or piezoelectric properties and is used as an electronic component, or the electrical device using it.
3. Something that has the form of a crystal; for example, a frozen snowflake or a grain of salt.
4. A heavy transparent sparkling glass or household crystal glass objects made from heavy transparent sparkling glass.
5. Etymology: from Old English cristal, "clear ice, clear mineral", from Old French cristal, 12th century, Modern French crystal; from Latin crystallus, "crystal, ice"; from Greek krystallos, from kryos, "frost".
2. A crystal in which the lattice-site occupants are charged ions held together primarily by their electrostatic interaction.
3. A crystal formed of an array of positive and negative ions held together by electrostatic forces.
Just as electronic bandgaps (energy difference between a non-conductive state and the conductive state) prevent electrons from passing through, photonic crystals create photonic bandgaps that confine light.
This technology increases the efficiency in optical fibers and allows microscopic lasers to be built. It is also expected to be used in the construction of photonic circuits that can stand alone or be integrated into semiconductor circuits.
Piezoelectricity has the function of certain crystals to generate a voltage in response to applied mechanical stress.
The result is reversible in that the piezoelectric crystals, subject to an externally applied voltage, can change shape by a minimal amount.
The change is in the degree of nanometers although there are useful applications; such as, the production and detection of sound, the generation of high voltages, electronic frequency generation, and the ultrafine focusing of optical assemblies.
A characteristic known as pyroelectricity, which is the ability of certain mineral crystals to generate electrical charges when heated, was determined as early as the 18th century, and was named by David Brewster in 1824.
In 1880, the brothers Pierre Curie and Jacques Curie predicted and demonstrated piezoelectricity using tinfoil, glue, wire, magnets, and a jeweler's saw.
They showed that crystals of tourmaline, quartz, topaz, cane sugar, and Rochelle salt (sodium potassium tartrate tetrahydrate) generate electrical polarization from mechanical stress.
Quartz and Rochelle salt exhibited the most piezoelectricity. There are twenty known natural crystal classes that exhibit direct piezoelectricity.
2. A mineral, especially a transparent form of quartz, having a crystalline structure, often characterized by external planar faces.
The most widely used technique for making single-crystal silicon, in which a seed of single-crystal silicon contacts the top of molten silicon.
As the seed is slowly raised, atoms of the molten silicon solidify in the pattern of the seed and extend the single-crystal structure.