perovskite

pe·rovsk·ite

P5218650 (pə-rŏvz′kīt′, -rŏfs′-)n.1. A relatively rare yellow, brown, or black mineral, CaTiO₃, sometimes containing rare-earth elements such as lanthanum. 2. Any of various oxides having a crystal structure similar to that of this mineral and that can be found in many superconducting ceramic materials and in electrodes in fuel cells.

[After Count Lev Alekseyevich Perovski (1792-1856), Russian mineralogist.]

perovskite

(pɛˈrɒvskaɪt) n (Minerals) a yellow, brown, or greyish-black mineral form of calcium titanate with some rare-earth elements, which is used in certain high-temperature ceramic superconductors[C19: named after Count Lev Alekseevich Perovski (1792–1856), Russian statesman]

pe•rovsk•ite

(pəˈrɒf skaɪt, -ˈrɒv-)

n. 1. a rare titanate mineral, CaTiO₃, forming yellow, brown, or black cubic crystals. 2. any of a family of superconducting ceramics with an atomic structure resembling that of this mineral. [1835–45; < German Perowskit, after Count Lev Alekseevich Perovskiĭ (1792–1856), Russian statesman; see -ite¹]

perovskite

[pə′rävz‚kīt] (mineralogy) Ca[TiO₃] A natural, yellow, brownish-yellow, reddish, brown, or black mineral and a structure type which includes no less than 150 synthetic compounds; the crystal structure is ideally cubic, it occurs as rounded cubes modified by the octahedral and dodecahedral forms, luster is subadamantine to submetallic, hardness is 5.5 on Mohs scale, and specific gravity is 4.0.

Perovskite

(named for L. A. Perovskii). (1) A mineral of the oxide class. The chemical formula of perovskite is CaTiO₃, with CaO accounting for 41.24 percent of the composition, and TiO₂ for 58.76 percent. Perovskite that contains admixtures of Ce is called knopite; of Ni, Ce, and Fe, dysanalite; and of Na, Ce, Ti, and Nb, loparite.

Perovskite crystallizes in the pseudoisometric system. Each calcium atom is surrounded by 12 oxygen atoms, which are located at the apexes of a cuboctahedron; the coordination number of Ti is eight. Characteristic striations appear on the cubic faces parallel to the edges. Cleavage is cubic, hardness is 5.5–6 on Mohs’ scale, and the density ranges from 3,950 to 4,040 kg/m³. The color may be black, grayish black, or brownish.

Perovskite frequently occurs in ultrabasic alkaline rocks, including olivinites, pyroxenes, and kimberlites, as well as in associated ore segregations and carbonatites. It fills the interstices at the point of contact of basic rocks with limestone; it also is interstitially distributed in chloritic shale and in nephelinic, leu-citic, and melilitic basalts.

Knopite is used as a source of rare-earth elements of the cerium group, and loparite is a source of niobium and titanium.

(2) A group of chemical compounds whose crystal structure resembles that of perovskite [in English usage “perovskite” is the adjectival noun that denotes the structure type of these compounds and not the compounds themselves]. Perovskites have the general formula ABX₃, where A is a tetravalent cation, B is a heptavalent cation, and X is an anion—usually oxygen, as in NaNbO₃ and BaTiO₃. Many of these compounds are ferroelectric, including BaTiO₃ and LiNbO₃; the group also includes some superconductors (for example, SrTiO₃), semiconductors, and compounds that display magnetic ordering.

perovskite

An oxide mineral made up of calcium titanate that is expected to be commercialized in higher-efficiency solar cells in the 2020-2021 time frame. Named after Russian mineralogist Lev Perovski, who discovered it in the 1800s, perovskite may also be employed as quantum dots in future screen technologies due to its high color purity. See quantum dot.

Automatic Solar Cell Window Shades
In 2018, using perovskite and carbon nanotube technologies, the National Renewable Energy Lab in Golden, Colorado developed clear window glass that emits electricity and darkens with sunshine. When the sun fades, the window becomes transparent again. The transparency range is 3% to 68%.

单词	perovskite
释义	perovskite pe·rovsk·ite P5218650 (pə-rŏvz′kīt′, -rŏfs′-)n.1. A relatively rare yellow, brown, or black mineral, CaTiO₃, sometimes containing rare-earth elements such as lanthanum. 2. Any of various oxides having a crystal structure similar to that of this mineral and that can be found in many superconducting ceramic materials and in electrodes in fuel cells. [After Count Lev Alekseyevich Perovski (1792-1856), Russian mineralogist.] perovskite (pɛˈrɒvskaɪt) n (Minerals) a yellow, brown, or greyish-black mineral form of calcium titanate with some rare-earth elements, which is used in certain high-temperature ceramic superconductors[C19: named after Count Lev Alekseevich Perovski (1792–1856), Russian statesman] pe•rovsk•ite (pəˈrɒf skaɪt, -ˈrɒv-) n. 1. a rare titanate mineral, CaTiO₃, forming yellow, brown, or black cubic crystals. 2. any of a family of superconducting ceramics with an atomic structure resembling that of this mineral. [1835–45; < German Perowskit, after Count Lev Alekseevich Perovskiĭ (1792–1856), Russian statesman; see -ite¹] perovskite perovskite [pə′rävz‚kīt] (mineralogy) Ca[TiO₃] A natural, yellow, brownish-yellow, reddish, brown, or black mineral and a structure type which includes no less than 150 synthetic compounds; the crystal structure is ideally cubic, it occurs as rounded cubes modified by the octahedral and dodecahedral forms, luster is subadamantine to submetallic, hardness is 5.5 on Mohs scale, and specific gravity is 4.0. Perovskite (named for L. A. Perovskii). (1) A mineral of the oxide class. The chemical formula of perovskite is CaTiO₃, with CaO accounting for 41.24 percent of the composition, and TiO₂ for 58.76 percent. Perovskite that contains admixtures of Ce is called knopite; of Ni, Ce, and Fe, dysanalite; and of Na, Ce, Ti, and Nb, loparite. Perovskite crystallizes in the pseudoisometric system. Each calcium atom is surrounded by 12 oxygen atoms, which are located at the apexes of a cuboctahedron; the coordination number of Ti is eight. Characteristic striations appear on the cubic faces parallel to the edges. Cleavage is cubic, hardness is 5.5–6 on Mohs’ scale, and the density ranges from 3,950 to 4,040 kg/m³. The color may be black, grayish black, or brownish. Perovskite frequently occurs in ultrabasic alkaline rocks, including olivinites, pyroxenes, and kimberlites, as well as in associated ore segregations and carbonatites. It fills the interstices at the point of contact of basic rocks with limestone; it also is interstitially distributed in chloritic shale and in nephelinic, leu-citic, and melilitic basalts. Knopite is used as a source of rare-earth elements of the cerium group, and loparite is a source of niobium and titanium. (2) A group of chemical compounds whose crystal structure resembles that of perovskite [in English usage “perovskite” is the adjectival noun that denotes the structure type of these compounds and not the compounds themselves]. Perovskites have the general formula ABX₃, where A is a tetravalent cation, B is a heptavalent cation, and X is an anion—usually oxygen, as in NaNbO₃ and BaTiO₃. Many of these compounds are ferroelectric, including BaTiO₃ and LiNbO₃; the group also includes some superconductors (for example, SrTiO₃), semiconductors, and compounds that display magnetic ordering. perovskite An oxide mineral made up of calcium titanate that is expected to be commercialized in higher-efficiency solar cells in the 2020-2021 time frame. Named after Russian mineralogist Lev Perovski, who discovered it in the 1800s, perovskite may also be employed as quantum dots in future screen technologies due to its high color purity. See quantum dot. Automatic Solar Cell Window Shades In 2018, using perovskite and carbon nanotube technologies, the National Renewable Energy Lab in Golden, Colorado developed clear window glass that emits electricity and darkens with sunshine. When the sun fades, the window becomes transparent again. The transparency range is 3% to 68%. MedicalSeequantum dot
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