Dielectric Behavior and Spontaneous Polarization as a Consequence of Berry Quantum Phase Effect: The case of La2NiMnO6 Double Perovskite—A New Approach to Polarization. Issue 4 (6th February 2022)

• Record Type: Journal Article
• Authors: Najar, Feroz A.; Samad, Rubiya; Sultan, Khalid; Ahmad, Hilal; Qaudir, Irshad; Nisa, Shams Un; Batool, Bushra; Fatima, Shanas
• Is Part Of: Physica status solidi. Volume 259:Issue 4(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-02-06
• Subjects: berry phase -- density functional theory -- dielectric constant -- double perovskites -- polarization; Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.202100587
• Languages: English
• ISSNs: 0370-1972

Abstract

Abstract : Transition metal oxides have been the materials of interest in modern‐day science and technology. Among these materials, double perovskites have been studied very often. To explore such types of oxides and to provide a better understanding especially about lanthanum manganates, herein, the system of La2 NiMnO6 is investigated, which exists in two phases, viz., monoclinic and rhombohedral via density functional theory. So far, the monoclinic phase which usually exists at low temperatures has been probed a lot; however, very little information is available about the rhombohedral phase and thus needs to be investigated. Herein, the rhombohedral phase of the material is simulated and various properties like band structure, electronic distribution of states, and absorption within the material are investigated. The study of the complex dielectric nature of the material and its refractive index with frequency variations of the incident field is also presented. The self‐interactions have been taken care‐off taking the Hubbard parameter into account. The spontaneous polarization for the first time as a berry phase using a quantum mechanical approach has also been calculated. The high dielectric constant at visible frequencies ensures the potential use of this material in the case of storage devices. Abstract : The article reports the first‐principle studies of the rhombohedral ferroelectric phase of the material. The band structure and the density of states unveil the semiconducting nature of the material with a bandgap value of about 1.38 eV approximately. The spontaneous polarization as a berry phase of Bloch wave functions estimated using the quantum mechanical modern theory of polarization indicates that macroscopic polarization is a multivalued quantity and forms a lattice contrary to the polarization calculated experimentally which is single valued.