Study of the electronic and magnetic properties of A2Ti2O7 (A=Er, Tb)

Khorasani, E.; Alaei, N. Deyli-Nazar M.; Shahbazi, F.
June 2014
Iranian Journal of Physics Research;2014, Vol. 14 Issue 1, p4
Academic Journal
The geometrical frustration in the magnetic pyrochlore oxides causes interesting properties at low temperatures in these materials. Therefore, we studied two challenging materials, Er2Ti2O7 and Tb2Ti2O7, using an ab intio method, based on Density Functional Theory (DFT). To take into account the f electrons coulomb interactions correctly, we employed DFT+U, a Hubbard method correction. As spin-orbit coupling (SOC) is very effective in these materials, we added SOC to the DFT+U calculations (DFT+U+SOC). Using DFT+U+SOC, we examined the effect of non-collinear magnetism. The DFT+U+SOC calculations give rise to the magnetic moments 8.2 µB and 7.1 µB for Er2Ti2O7 and Tb2Ti2O7, respectively. These values deviate from the experimental results. The reason is that the DFT calculations are trapped in the local minima, indicatinglhat we need more sophisticated methods to find the global minimum in our electronic structure calculations. Although we need structural optimization to find better magnetic moment values, unfortunately it is possible to reach incorrect structural optimization if the electronic structural optimization for finding global minima is not performed correctly.


Related Articles

  • Structure, lattice dynamics, and exchange interaction in LuVO, YVO: an ab initio approach. Nazipov, D.; Nikiforov, A.; Chernyshev, V. // Optics & Spectroscopy;Oct2016, Vol. 121 Issue 4, p544 

    Ab initio calculations of the crystal structure and fundamental vibrations of vanadium pyrochlores LuVO and YVO are performed. The calculations are performed in the framework of the density functional theory (DFT) with the use of hybrid functionals. The ions involved in the vibrations are...

  • Magnetic Ground State and Electronic Structure Calculations of PbMnO3 using DFT. Subramanian, Sathya Sheela; Natesan, Baskaran // Advanced Materials Research;2014, Issue 895, p420 

    Structural optimization, magnetic ground state and electronic structure calculations of tetragonal PbMnO3 have been carried out using local density approximation (LDA) implementations of density functional theory (DFT). Structural optimizations were done on tetragonal P4mm (non-centrosymmetric)...

  • Electronic structure calculations for magnetic systems. Richter, Manuel // Studia Universitatis Babes-Bolyai, Physica;2015 Special Issue, Vol. 60, p41 

    The article presents a preface to the journal "Electronic structure calculations for magnetic systems" by scientific, technical and medical information provider Manuel Richter.

  • Density functional theory of two-dimensional electron–hole complexes. Vasilchenko, Alexander A. // Modern Physics Letters B;Apr2019, Vol. 33 Issue 12, pN.PAG 

    The energy of the two-dimensional electron–hole complex has been calculated in the framework of the density functional theory. We show that the energy of a direct two-dimensional exciton, without taking into consideration the exchange–correlation interaction, is very different from...

  • Ab Initio Approaches for Low‐Energy Spin Hamiltonians. Riedl, Kira; Li, Ying; Valentí, Roser; Winter, Stephen M. // Physica Status Solidi (B);Sep2019, Vol. 256 Issue 9, pN.PAG 

    Implicit in the study of magnetic materials is the concept of spin Hamiltonians, which emerge as the low‐energy theories of correlation‐driven insulators. In order to predict and establish such Hamiltonians for real materials, a variety of first principles ab initio methods have been...

  • First-principles investigations on structural, elastic and mechanical properties of BNAs ternary alloys. Zhang, Junqin; Ma, Huihui; Zhao, Bin; Wei, Qun; Yang, Yintang // International Journal of Modern Physics B: Condensed Matter Phys;May2018, Vol. 32 Issue 12, p-1 

    A systematic investigation of the structural optimization, elastic and mechanical properties of the BNAs ternary alloys are reported in the present work using the density-functional theory with the generalized gradient approximation (GGA) of the exchange-correlation functional. Some of the...

  • Enhancement of hydrogen storage properties of Ca3CH antiperovskite compound with hydrogen doping. Gencer, Aysenur; Surucu, Gokhan // International Journal of Energy Research;Jan2020, Vol. 44 Issue 1, p567 

    Summary: The doping effect of hydrogen on the Ca3CHx (x = 1, 4, 7, 9, and 10) antiperovskite compounds has been examined using density functional theory (DFT). The results of the structural optimizations show that all these compounds have negative formation energy implying the energetic...

  • Electronic Structure Studies and Photocatalytic Properties of Cubic Bi1.5ZnNb1.5O7. Perenlei, Ganchimeg; Alarco, Jose A.; Talbot, Peter C.; Martens, Wayde N. // International Journal of Photoenergy;9/3/2015, Vol. 2015, p1 

    The photocatalytic ability of cubic Bi1.5ZnNb1.5O7 (BZN) pyrochlore for the decolorization of an acid orange 7 (AO7) azo dye in aqueous solution under ultraviolet (UV) irradiation has been investigated for the first time. BZN catalyst powders prepared using low temperature sol-gel and higher...

  • BH-DFTB/DFT calculations for iron clusters. Aktürk, Abdurrahman; Sebetci, Ali // AIP Advances;2016, Vol. 6 Issue 5, p1 

    We present a study on the structural, electronic, and magnetic properties of Fen(n = 2 - 20) clusters by performing density functional tight binding (DFTB) calculations within a basin hopping (BH) global optimization search followed by density functional theory (DFT) investigations. The...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics