Modeling of Ferroelectric, Semiconducting and Superconducting Perovskite Oxides Using Crystalline Accommodation Law

Document Type : Original Article

Authors

Physics Department, Faculty of Science, Port Said University, Port Said, Egypt

Abstract

Perovskite oxides are very important materials for different applications because they have a variety of very interesting properties such as ferroelectric, antiferroelectric, ferromagnetic, antiferromagnetic, semiconducting and superconducting at low temperature. Since the success of crystalline accommodation law (CAL) in modeling perovskite halides, we aim in this work to use CAL for modeling perovskite oxides. Here we show that a perfect agreement with the results obtained for halides perovskite as the following: all perovskite oxides are formed at VEC = 4.8 and most of them crystallize in three systems; cubic, hexagonal and orthorhombic with the number of filled zones in the valence band respectively. It is also found that the dielectric ferroelectric perovskite oxides have the orthorhombic structure of primitive cell volume (VP) ranges from 143.58 to 286.93 Å3 corresponding to the volume of Brillouin zone (VB , volume of quantum state) ranges from 0.86 to 1.72 Å-3. On average, this is the smallest volume of quantum state. In the case of perovskite oxides, that can be converted into superconductor at low temperature, have cubic structure with VP ranges from 52.73 to 68.61 Å3 corresponding to VB ranges from 3.61 to 4.70 Å-3. On average, this is the largest volume of quantum state for example the compound SrTiO3. In between it is found that the compounds which have hexagonal structure are semiconducting with VP ranges from 108.73 to 130.43 Å3 corresponding to VB ranges from 1.90 to 2.28 Å-3. On the average, this is intermediate between orthorhombic and cubic.

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