YBa,Cu,O- as a defective perovskite Two types of Cu site pyramids Chains of vertex-linked Cuo, squares hese are indicated in a Polyhedral Representation Cuo2 KNiFa Structure (La, Sr) CuO(T Phase) KaNiF,is a derivative with deri structure of perovskite 9 structure. This structure the alternate stacking 0000 can be regarded as the o alternate stacking of 2D perovskite structure perovskite layer and aver and rocksalt tructure unit along c Ba Laz+v is K,NiF, structure, Tc(O)=g ↓ The same structure Cu with the first cupper F structure and its (110) projection La, Ba CuO (T 35K) Alternative Views of the La Cuo, Structure Alternative Views of the La Cuo Structure +Doped La, CuO, CuO, are the first HighT structure as based on SuperconductingOxide r 1. Sheets of elongated for which bednorz CuO. octahedra Miller Nobel Prize 2. Layered networks 中aCuO, may be viewed a t of Cu0 6, connected ABAB. arrangement of only by Last ions known as an AB Perovskite9 YBa2Cu3O7 as a Defective Perovskite Two types of Cu site Layers of CuO5 square pyramids Chains of vertex-linked CuO4 squares These are indicated in a Polyhedral Representation CuO2 BaO CuO BaO CuO2 Y CuO2 K2NiF4 Structure K2NiF4 structure and its (110) projection K2NiF4 is a derivative structure of perovskite structure. This structure can be regarded as the alternate stacking of 2D perovskite layer and Rocksalt Layer. BaxLa2-xCuO4-y is K2NiF4 structure，Tc(0)=38K (La,Sr)2CuO4 (T Phase) A superconductor with Derivative structure of K2NiF4 Can be regarded as the alternate stacking of perovskite structure unit containing Cu-O layer and rocksalt structure unit along c axis. The same structure with the first cupper oxide superconductors La2-xBaxCuO4 (Tc=35K). Doped La2CuO4 {La2-xSrxCuO4 and La2-xBaxCuO4 } are the first (1986) High-Tc Superconducting Oxide (Tc ~ 40 K) for which Bednorz & Müller were awarded a Nobel Prize La2CuO4 may be viewed as if constructed from an ABAB... arrangement of perovskite cells - known as an AB Perovskite! Alternative Views of the La2CuO4 Structure Alternative Views of the La2CuO4 Structure We may view the structure as based on: 1.Sheets of elongated CuO6 octahedra, sharing only vertices 2.Layered networks of CuO4 6- , connected only by La3+ ions