Perovskite Structure Compounds

Abstract

Compounds with the perovskite structure have been studied extensively because they show a wide variety of physical and chemical properties, and many of the properties are widely used in technological applications. Perovskites and perovskite‐related compounds arguably represent the most important, fundamental, and intriguing family of complex materials. In this chapter, a large variety of the perovskite structure compounds are reviewed and structural features of the fundamental compounds are highlighted. Because the diverse varieties of physical and chemical properties that the perovskite materials show are described in the following chapters, they will not be described in detail in this chapter. Some synthesis techniques for preparing perovskites are also focused on in different chapters.

Intergrowth between the Oxynitride Perovskite SrTaO2N and the Ruddlesden–Popper Phase Sr2TaO3N

“…Oxynitrides are attracting attention as promising white LED phosphors, photocatalysts, and dielectric materials. − However, the use of oxynitride perovskites is very challenging because their properties vary upon substituting their anions or cations . SrTaO 2 N crystallizes in the I 4/ mcm space group with a = 0.569411(7) nm and c = 0.80658(2) nm .…”

crystIT: Complexity and Configurational Entropy of Crystal Structures via Information Theory

“…Having a closer look at the iconic material class of perovskites, it is interesting to look for correlations between tilt systems and complexity as represented by I G . For the classification of perovskite tilts after the Glazer (1972) notation we would like to refer to some insightful book chapters and reviews (Shimakawa, 2017;Woodward, 1997).…”

Synergistic Influence of d0 (Nb5+) and d10 (Cd2+) Cations in Stabilizing Noncentrosymmetric Dion–Jacobson Layered Perovskites, A′Cd2Nb3O10 (A′ = Rb, Cs)

“…In this aspect, the probability of identifying materials with the desired structures and properties is higher among the structural families that are flexible in terms of accommodating a wide range of cations and anions. For example, inorganic solids belonging to the families of perovskites and layered perovskites have often proven to be the most suitable functional materials because they exhibit several interesting physical properties such as conducting, superconducting, thermoelectric, magnetic, dielectric, ferroelectric, etc. − Particularly, among the layered perovskites, the families of Aurivillius oxides (AV; (Bi 2 O 2 )­[A n –1 B n O 3 n +1 ]), , Ruddlesden–Popper oxides (RP; A′ 2 [A n –1 B n O 3 n +1 ]), , and Dion–Jacobson series of oxides (DJ; A′[A n –1 B n O 3 n +1 ]) − have widely attracted the attention of researchers. − All of these layered perovskites possess the common perovskite blocks [A n –1 B n O 3 n +1 ], with n being the number of BO 6 octahedra representing the thickness of the perovskite slabs where A represents the cations (e.g., Ca 2+ , Sr 2+ , La 3+ , and Bi 3+ ) in the perovskite blocks. A′ (Li, Na, K, Rb, and Cs) ions in RP and DJ oxides represent the interlayer cations.…”

“…Commonly, the corner-linked BO 6 octahedra in many perovskites (ABO 3 ) undergo certain rotations and tilts to stabilize the A cations that are smaller in size with a reduction in the symmetry to the orthorhombic structure (e.g., CaTiO 3 , with space group Pbnm ). The overall tilts and distortions based on their directions and magnitudes, in turn, result in individual centrosymmetric or NCS space groups and crystallographic structures in the ABO 3 perovskites. − In the case of layered perovskites, the combination of octahedral rotations in the x and y axes along with that in the z axis results in displacement of the A cation in the perovskite blocks [A n –1 B n O 3 n +1 ]. The collective octahedral rotations and A-cation displacements prohibiting the formation of structures with inversion symmetry have been explained in detail in several of the layered perovskites. , Topochemical fluorination of RP n = 2 members (La 3 Ni 2 O 7 ) was shown by Hayward et al to enhance the structural distortions leading to the formation of NCS structures (La 3 Ni 2 O 5.5 F 3.5 ).…”

“…Our interest has been to explore the formation of layered perovskites by varying the A cations in the DJ-based layered perovskite blocks [A n –1 B n O 3 n +1 ]. Even a small mismatch in the sizes of the A cations to the sizes of the B cations resulted in distortions that are commonly referred to as chemical pressure in the ABO 3 perovskites and are responsible for the significant changes in the physical properties . Toward this goal, first, we envisaged the incorporation of a d 10 ion such as Cd 2+ in the A cationic sites, while keeping a d 0 ion (Nb 5+ ) in the B cationic sites of the DJ n = 3 layered perovskites A′[A n –1 B n O 3 n +1 ] (A′ = Rb, Cs).…”