钙钛矿结构Perovskite (structure)

理想立方钙钛矿空间群为 Pm3̄m。1926 年戈尔德施密特提出容差因子 t = (r_A + r_X)/[√2(r_B + r_X)]，t 在约 0.8–1.0 之间时钙钛矿结构稳定，t 接近 1 时为立方，偏离时八面体倾转，结构畸变为四方、正交或菱方。这种可调的畸变和对掺杂的广泛容忍，使钙钛矿家族具有极其丰富的物理性质。

The ideal cubic perovskite has space group Pm3̄m. In 1926 Goldschmidt introduced the tolerance factor t = (r_A + r_X)/[√2(r_B + r_X)]; the structure is stable for t between about 0.8 and 1.0, cubic when t is near 1, and when t departs from 1 the octahedra tilt and the structure distorts to tetragonal, orthorhombic or rhombohedral. This tunable distortion and wide tolerance of substitution give the perovskite family exceptionally rich physics.

1839 年德国矿物学家古斯塔夫·罗泽在俄国乌拉尔山发现钙钛矿，以俄国矿物学家佩罗夫斯基（L. A. Perovski）的名字命名。1945 年前后发现钛酸钡 BaTiO₃ 的铁电性。2009 年宫坂力等首次把有机-无机杂化卤化铅钙钛矿 CH₃NH₃PbI₃ 用于太阳能电池，效率 3.8%，十几年内提升到 26% 以上。

In 1839 the German mineralogist Gustav Rose found perovskite in the Ural Mountains and named it after the Russian mineralogist L. A. Perovski. The ferroelectricity of barium titanate, BaTiO₃, was discovered around 1945. In 2009 Miyasaka and co-workers first used the hybrid lead halide perovskite CH₃NH₃PbI₃ in a solar cell at 3.8% efficiency, a figure that rose above 26% within about fifteen years.

钛酸钡用于多层陶瓷电容器，锆钛酸铅（PZT）是最重要的压电陶瓷；镧锶锰氧具有庞磁阻效应；铜氧化物高温超导体由钙钛矿衍生；镧锶钴铁氧用作固体氧化物燃料电池阴极；卤化物钙钛矿用于高效太阳能电池、发光二极管和 X 射线探测器。地球下地幔的主要矿物布里奇曼石（MgSiO₃）也是钙钛矿结构，被认为是地球上最丰富的矿物。

Barium titanate is used in multilayer ceramic capacitors, and lead zirconate titanate (PZT) is the most important piezoelectric ceramic; lanthanum strontium manganites show colossal magnetoresistance; the cuprate high-temperature superconductors derive from perovskites; lanthanum strontium cobalt ferrite is a solid-oxide fuel-cell cathode; and halide perovskites make efficient solar cells, LEDs and X-ray detectors. Bridgmanite (MgSiO₃), the main mineral of the lower mantle and thought to be the most abundant mineral on Earth, also has the perovskite structure.