Effects of on-site Coulomb interaction (U) on the structural and electronic properties of half-metallic ferromagnetic orthorhombic Pr0.75Na0.25MnO3 manganite: A LDA + U calculation and experimental study

• 出版年: Materials Research Express
• 第一著者: 2-s2.0-85021788952
• フォーマット: 論文
• 言語: English
• 出版事項: Institute of Physics Publishing 2017
• オンライン･アクセス: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85021788952&doi=10.1088%2f2053-1591%2faa7437&partnerID=40&md5=e217b447cc0dc8ea535c973ee4c8353c

In this study, the structural, electronic, and half-metallic properties of monovalent-doped Pr0.75Na 0.25MnO3 manganite were investigated via density functional theory (DFT) with local density approximation (LDA) and local densit y approximation plus Hubbard U parameter (LDA + U). The effect of on-site Coulomb interaction on the structural and electronic properties of REMn O3 (RE = Pr, Nd, La) manganites, which consist of strongly interacting RE 4f and transition metal Mn 3d electrons, were studied. The strong Coulomb repulsion between electrons was corrected using the Hubbard parameter U, which ranged from 2 to 6 eV for Mn 3d and was set at 6 eV for Pr 4f. The calculated results showed that the structural parameters, charge and spin densities, and the total and partial densities of states of Pr0.75Na0.25M n O3 manganite were sensitive to the change in U value. The crystal structure and energy band gap of Pr0.75Na0.25MnO3 manganite were calculated using LDA + U with the optimized U value of 2 eV for Mn3d. The results calculated with a U value of 2 eV showed better agreement with the experimental data compared with those calculated with U values of 4 eV and 6 e V. Interestingly, the LDA + U-based calculations revealed that Pr0.75Na0.25MnO3 manganite has a half-metallic ferromagnetic character. The majority-spin electrons exhibited metallic behavior, whereas the minority-spin electrons exhibited insulating gaps of 2.50, 3.28, and 4.20 eV for the U values of 2, 4, and 6 eV, respectively. The calculated band structure and density of states indicated that the on-site Coulomb repulsion U significantly influenced the hybridization of O2p with Mn3d or bitals at the valence and conduction bands. © 2017 IOP Publishing Ltd.