Evans Hayden A, Wu Yue, Seshadri Ram, Cheetham Anthony K
Materials Research Laboratory, University of California, Santa Barbara CA, USA.
National Institute of Standards and Technology, Center for Neutron Research Gaithersburg, MD, USA.
Nat Rev Mater. 2020;5. doi: 10.1038/s41578-019-0160-x.
Materials with the perovskite ABX structure play a major role across materials chemistry and physics as a consequence of their ubiquity and wide range of useful properties. ReO-type structures can be described as ABX perovskites in which the A-cation site is unoccupied, giving rise to the general composition BX, where B is typically a cation and X is a bridging anion. The chemical diversity of such structures is extensive, ranging from simple oxides and fluorides, such as WO and AlF, to complex structures in which the bridging anion is polyatomic, such as in the Prussian blue-related cyanides Fe(CN) and CoPt(CN). The same ReO-type structure is found in metal-organic frameworks, for example, ln (im)(im = imidazolate) and the well-known MOF-5 structure, where the B-site cation is polyatomic. The extended 3D connectivity and openness of this structure type leads to compounds with interesting and often unusual properties. Notable among these properties are negative thermal expansion (for example, ScF), photocatalysis (for example, CoSn(OH)), thermoelectricity (for example, CoAs) and superconductivity in a phase that is controversially described as SH with a doubly interpenetrating ReO structure. We present an account of this exciting family of materials and discuss future opportunities in the area.
具有钙钛矿ABX结构的材料因其广泛存在和众多有用特性，在材料化学和物理学领域发挥着重要作用。ReO型结构可描述为ABX钙钛矿，其中A阳离子位点未被占据，形成一般组成BX，其中B通常为阳离子，X为桥连阴离子。这类结构的化学多样性很广泛，从简单的氧化物和氟化物，如WO和AlF，到桥连阴离子为多原子的复杂结构，如普鲁士蓝相关的氰化物Fe(CN)和CoPt(CN)。在金属有机框架中也发现了相同的ReO型结构，例如ln (im)(im =咪唑盐)和著名的MOF-5结构，其中B位阳离子是多原子的。这种结构类型的三维连通性和开放性导致化合物具有有趣且常常不寻常的性质。这些性质中值得注意的有负热膨胀（例如，ScF）、光催化（例如，CoSn(OH)）、热电性（例如，CoAs）以及在一个被有争议地描述为具有双互穿ReO结构的SH相中的超导性。我们介绍了这一令人兴奋的材料家族，并讨论了该领域未来的机遇。
