相关论文: First-principles study of orthorhombic CdTiO3 pero…
The first-principles calculations have been performed to investigate the ground state properties of cubic scandium trifluoride (ScF$_3$) perovskite. Using modified hybrid exchange-correlation functionals within the density functional theory…
Using the full-potential linearized-augmented-plane-wave (FLAPW) method, we have analyzed systematically the trends in the structural and electronic properties of the 3d and 4d transition-metal oxides SrMO_3 (M = Ti, V, Zr and Nb). The…
The hyperfine interaction between the quadrupole moment of atomic nuclei and the electric field gradient (EFG) provides information on the electronic charge distribution close to a given atomic site. In ferroelectric materials, the loss of…
We analyze recent measurements [R. Blinc, V. V. Laguta, B. Zalar, M. Itoh and H. Krakauer, J. Phys. : Cond. Mat., v.20, 085204 (2008)] of the electric field gradient on the oxygen site in the perovskites SrTiO3 and BaTiO3, which revealed,…
While the tetragonal antiferro-electrically distorted (AFD) phase with space group $I4/mcm$ is well known for SrTiO$_3$ to occur below 105 K, there are also some hints in literature of an orthorhombic phase, either at lower temperature at…
Perturbed angular correlation spectroscopy combined with $ab-initio$ electronic structure calculations is used to unravel the structural phase transition path from the low-temperature polar structure to the high-temperature structural phase…
First principles calculations are used to investigate the effects of epitaxial strain on the structure of the perovskite oxide CaTiO$_3$, with particular focus on the stabilization of a ferroelectric phase related to a polar instability…
Structural and optoelectronic properties of BaThO3 cubic perovskite are calculated using all electrons full potential linearized augmented plane wave (FP-LAPW) method. Wide and direct band gap, 5.7 eV, of the compound predicts that it can…
The crystal structures and phonon spectra of orthorhombic cadmium titanate with the $Pbnm$ structure and of its two possible ferroelectrically distorted phases with $Pbn2_1$ and $Pb2_1m$ space groups were calculated from first principles…
We extend our previous first-principles theory for perovskite ferroelectric phase transitions to treat also antiferrodistortive phase transitions. Our approach involves construction of a model Hamiltonian from a Taylor expansion,…
The lattice constants of Strontium titanate perovskite has been studied using the Density functional theory formalism at the PBE and the HSE levels of theory. The study has been done in all the 3 existing phases; namely cubic, orthorhombic…
The time-differential perturbed-angular-correlation (TDPAC) technique was applied to the study of the internal electric-field gradient (EFG) in Eu- and Ho-sesquioxides in their cubic bixbyite phases. The results, as well as previous…
With the aim to get an insight in the origin of differences in the earlier reported calculation results for KNbO3 and to test the recently proposed implementation of the FP-LMTO method by Methfessel and van Schilfgaarde, we perform a…
In this work, theoretical investigation of cubic Pm-3m phase RbGeO3 germanate perovskite using plain wave basis, density function theory (DFT) is conducted. DFT modelling calculations, clearly shows that this perovskite exhibits…
We present the results of first-principles calculations on two possible terminations of the (001) surfaces of SrTiO3 (STO), BaTiO3 (BTO), and PbTiO3 (PTO) perovskite crystals. Atomic structure and the electronic configurations were…
The perovskite crystal BaTiO3 is modeled using a first-principles based effective Hamiltonian and molecular dynamics simulations are performed to estimate the pyroelectric response. The electrocaloric temperature change, \DeltaT, is…
Density Functional Tight-Binding (DFTB), an approximative approach derived from Density Functional Theory (DFT), has the potential to pave the way for simulations of large periodic or non-periodic systems. We have specifically tailored DFTB…
Entirely inorganic perovskites have attracted enormous attention of late owing to their outstanding applications in optoelectronics including highly stable perovskite solar cells. In-depth understanding of the optoelectronic and transport…
A first-principles study of the vibrational modes of PbTiO_3 in the ferroelectric tetragonal phase has been performed at all the main symmetry points of the Brillouin zone (BZ). The calculations use the local-density approximation and…
The lattice instabilities of perovskite structure oxides are responsible for many of their interesting properties, such as temperature-dependent ferroelectric phase transitions. First-principles calculations using linear response theory…