0000000000006824
AUTHOR
Inta Isakoviča
First Principles Calculations of Atomic and Electronic Structure of TiAl3+- and TiAl2+-Doped YAlO3
In this paper, the density functional theory accompanied with linear combination of atomic orbitals (LCAO) method is applied to study the atomic and electronic structure of the Ti3+ and Ti2+ ions substituted for the host Al atom in orthorhombic Pbnm bulk YAlO3 crystals. The disordered crystalline structure of YAlO3 was modelled in a large supercell containing 160 atoms, allowing simulation of a substitutional dopant with a concentration of about 3%. In the case of the Ti2+-doped YAlO3, compensated F-center (oxygen vacancy with two trapped electrons) is inserted close to the Ti to make the unit cell neutral. Changes of the interatomic distances and angles between the chemical bonds in the de…
First Principles Calculations of Atomic and Electronic Structure of Ti3+Al- and Ti2+Al-Doped YAlO3
M.G.B. appreciates support from the Chongqing Recruitment Program for 100 Overseas Innovative Talents (grant no. 2015013), the Program for the Foreign Experts (grant no. W2017011), Wenfeng High-end Talents Project (grant no. W2016-01) offered by the Chongqing University of Posts and Telecommunications (CQUPT), Estonian Research Council grant PUT PRG111, European Regional Development Fund (TK141), and NCN project 2018/31/B/ST4/00924. This study was supported by a grant from Latvian Research Council No. LZP-2018/1-0214 (for AIP). Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Program H202…
Time-Dependent Density Functional Theory Calculations of N- and S-Doped TiO2 Nanotube for Water-Splitting Applications
This research was funded by the Latvian Council of Science grant LZP-2018/2-0083. Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union?s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART2.
Ab initio calculations of the electronic structure for Mn2+-doped YAlO3 crystals
The electronic structure of Mn2+ ion substituted for the host Y atom in orthorhombic bulk YAlO3 crystals has been calculated by means of hybrid exchange-correlation functional HSE within density functional theory. The supercell approach has been used to simulate in Pbnm YAlO3 crystal the point defects, Mn-dopant and compensated the F+ center (oxygen vacancy with one trapped electron), to make unit cell neutral. Large 2 × 2 × 2 supercells of 160 atoms allow us to simulate substitutional point defect with concentration of about 3%. Mn2+ ions substituting for host Y form covalent Mn–O bonds, in opposite to the mostly ionic Y–O bond. The F center inserted to compensate the Mn2+ dopant in YAlO3 …
Electronic structure of MnAl3+- and MnAl2+-doped YAlO3: Prediction from the first principles
Abstract The atomic structure and electronic properties of Mn3+ and Mn2+ ions substituted for the host Al at YAlO3 have been studied from the first principles. The 2 × 2 × 2 supercell adopted for the bulk crystal phase of P b n m symmetry allows us to simulate substitutional point defect with concentration of about 3%. To perform ab initio modeling of Mn-doped YAlO3 we were using approach of hybrid exchange-correlation functional HSE within density functional theory. We predict a decrease of the Mn O bond covalency in the doped crystal with respect to the Al O bond of ideal orthorhombic YAlO3. Relatively large displacement of Y and Al atoms nearest to the F 0 -center inserted to stabilize t…
Raman spectra of vacancy-containing LiF: Predictions from first principles
Abstract The electronic structure and Raman scattering from face-centered cubic LiF with three types of vacancies — an F-center, an F ′ -center and a vacancy without electrons ( v F ) — has been calculated by means of hybrid exchange–correlation functional within density functional theory. Our modeling predicts the effective charge of 0.87 e , 1.50 e and 0.10 e on the defect, respectively. The F-center induces two in-gap energy levels for two spin states split by 3.4 eV, while the F ′ -center and the v F induce a single in-gap level 3.8 eV and 2.9 eV below the bottom of conduction band, respectively. The calculated Raman spectra are thoroughly discussed and are found to match well the earli…
Atomic structure of manganese-doped yttrium orthoaluminate
Abstract Using hybrid exchange-correlation functional within density functional theory we have performed first-principle total energy calculations of Mn-doped yttrium orthoaluminate (YAlO3). Its equilibrium atomic structure has been predicted through optimization of coordinates of all atoms using a supercell approach. In our research both Mn3+ and Mn2+ ions have been substituted for the host alumina atom at orthorhombic Pbnm unit cell of YAlO3. F-center has been implemented as charge-compensating defect in case, when Mn2+ dopant is under study. In this study we thoroughly analyze the atomic displacements in seven nearest to Mn ion coordination spheres. Insertion of isoelectronic substitutio…