ab initio study of oxygen vacancy effects on structural, electronic and thermoelectric behavior of AZr1-xMxO3 (A = Ba, Ca, Sr; M= Al, Cu, x = 0.25) for application of memory devices

Ejaz Ahmad Khera; Hafeez Ullah; Muhammad Imran; Niaz Ahmad Niaz; Fayyaz Hussain; R M Arif Khalil; Umbreen Resheed; Anwar Manzoor Rana; Muhammad Iqbal Hussain; Chandreswar Mahata; Sungjun Kim

doi:10.1016/j.jmgm.2020.107825

ab initio study of oxygen vacancy effects on structural, electronic and thermoelectric behavior of AZr_1-xM_xO₃ (A = Ba, Ca, Sr; M= Al, Cu, x = 0.25) for application of memory devices

J Mol Graph Model. 2021 Mar:103:107825. doi: 10.1016/j.jmgm.2020.107825. Epub 2020 Dec 21.

Authors

Affiliations

¹ Department of Physics,The Islamia University of Bahawalpur, Pakistan.
² Department of Physics, Govt. College University Faisalabad, 38000, Pakistan.
³ Materials Simulation Research Laboratory (MSRL), Department of Physics, Bahauddin Zakariya University Multan Pakistan, 60800, Pakistan.
⁴ Materials Simulation Research Laboratory (MSRL), Department of Physics, Bahauddin Zakariya University Multan Pakistan, 60800, Pakistan. Electronic address: fayyazhussain248@yahoo.com.
⁵ Materials Simulation Research Laboratory (MSRL), Department of Physics, Bahauddin Zakariya University Multan Pakistan, 60800, Pakistan. Electronic address: muhammadarif@bzu.edu.pk.
⁶ Materials Simulation Research Laboratory (MSRL), Department of Physics, Bahauddin Zakariya University Multan Pakistan, 60800, Pakistan. Electronic address: anwarmanzoor@bzu.edu.pk.
⁷ Materials Simulation Research Laboratory (MSRL), Department of Physics, Bahauddin Zakariya University Multan Pakistan, 60800, Pakistan; Department of Physics,University of Education, Lahore, 54000, Pakistan.
⁸ School of Electronics Engineering, Chungbuk National University, Cheongju, 28644, Republic of Korea.
⁹ Division of Electronics and Electrical Engineering, Dongguk University, Seoul, 04620, Republic of Korea.

PMID: 33429230
DOI: 10.1016/j.jmgm.2020.107825

Abstract

The structural, electronic and thermoelectric properties of AZr_1-xM_xO₃ (A = Ba, Ca, Sr; M = Al, Cu, x = 0.25) without and with an oxygen vacancy (Vo) have been unveiled using the Perdew-Burke-Ernzerhof Generalized Gradient Approximation (PBE-GGA) functional along with Tran-Blaha modified Becke-Jonhson (TB-mBJ)approximation based on Density Functional Theory (DFT) in the framework of WIEN2k code for memristors applications. Moreover, isosurface charge density plots have been calculated by using Vienna ab initio Simulation Package (VASP) simulation code. The analysis of structural parameters reveals that substituting Zr⁴⁺ with Al³⁺ and Cu²⁺ causes the lattice distortion which tends to increase in the presence of Vo along with dopant. The study of band structure, density of states (DOS) and isosurface charge density plots predict the enhanced charge conduction and formation of conducting filaments (CFs) for all composites with dopant and/or Vo. Moreover, spin polarized density of states for Cu doped composites has also been calculated to confirm the large exchange splitting of Cu-3d states. The thermoelectric characteristics of considered composites have also been explored using the Boltztrap code to better explain the semi-classical Boltzmann transport theory. Thermoelectric parameters confirm the semiconductor nature of all composites, ensuring the compatibility for memristors and thermoelectric devices applications. In addition to this spin polarized thermoelectric behavior of Cu doped composites that ensure the contribution of spin down (↓) states of Cu for charge transport mechanism. The SrZrCuO₃+Vo composite is found most promising candidate followed by BaZrCuO₃ for memristors applications while, CaZrCuO₃ is found most suitable amongst studied composites for thermoelectric devices.

Keywords: Boltztrap; DFT; DOS,CFs; TB-mBJ; Thermoelectric.

MeSH terms

Computer Simulation
Electric Conductivity
Electronics*
Oxygen*
Semiconductors

Substances

Oxygen