相关论文: First-principles study of pyroelectricity in GaN a…
We present a first-principles study of the relationship between stress, temperature and electronic properties in piezoelectric ZnO. Our method is a plane wave pseudopotential implementation of density functional theory and density…
We use molecular dynamics with a first-principles based shell model potential to study pyroelec- tricity in lithium niobate. We find that the primary pyroelectric effect is dominant, and pyroelec- tricity can be understood simply from the…
Pyroelectricity is a very promising phenomenon in three- and two-dimensional (2D) materials, but first-principles calculations have not so far been used to elucidate the underlying mechanisms. Here we report density-functional theory (DFT)…
We generalize a previously established ab initio approach-originally developed for hexagonal close-packed (hcp) metals-to accommodate solids with both internal and external degrees of freedom. This extension enables the thermodynamic and…
We report here the first observation of a pyroelectric effect in a non-polar semiconductor. This effect originates in the temperature dependent electric dipole of the p-n junction. The junction was illuminated by a chopped CO2 laser beam,…
We describe here the first comprehensive investigation of a pyroelectric response of a p-n junction in a non-polar paraelectric semiconductor. The pyroelectric effect is generated by the, temperature dependent, built-in electrical dipole…
We calculate the pyrocoefficient, static dielectric susceptibility profiles and its thickness dependence of ferroelectric thin films. Also, the temperature dependences of above quantities have been calculated. For the calculations we use…
Polaron binding energy and effective mass are calculated for semiconductors with wurtzite crystalline structure from the first order electron-phonon corrections to the self-energy. A recently introduced Frohlich-like electron-phonon…
We carry out a completely first-principles study of the ferroelectric phase transitions in BaTiO$_3$. Our approach takes advantage of two features of these transitions: the structural changes are small, and only low-energy distortions are…
We report first principles density functional calculations of the spontaneous polarizations, piezoelectric constants and elastic constants for the II-VI wurtzite structure ZnO, MgO and CdO. Using our self interaction corrected…
We use first principles density functional theory calculations to investigate the effect of biaxial strain in the low-temperature structural and ferroelectric properties of [111]-oriented SrTiO$_3$. We find that [111] biaxial strain,…
Spin qubits associated with color centers are promising platforms for various quantum technologies. However, to be deployed in robust quantum devices, the variations of their intrinsic properties with the external conditions, and in…
The piezoelectric (PZ) polarization effect enhances the phonon group velocity in wurtzite nitrides. This enhancement influences the phonon relaxation rates. We calculate the modified phonon relaxation rates in binary wurtzite nitrides (GaN,…
An effective Hamiltonian for the ferroelectric transition in $PbTiO_3$ is constructed from first-principles density-functional-theory total-energy and linear-response calculations through the use of a localized, symmetrized basis set of…
Density Functional Theory calculations have been performed to obtain lattice parameters, elastic constants, and electronic properties of ideal pyrochlores with the composition A$_2$B$_2$O$_7$ (where A=La,Y and B=Ti,Sn,Hf, Zr). Some thermal…
The size effect on pyroelectric response of ferroelectric nanowires and nanotubes is analyzed. The pyroelectric coefficient strongly increases with the wire radius decrease and diverges at critical radius Rcr corresponding to the…
The dependence of the electrical conductivity on the oxygen partial pressure is calculated for the prototypical perovskite $\Ba\Ti\O_3$ based on data obtained from first-principles calculations within density functional theory. The…
We demonstrate that the frozen-ion contribution to the flexoelectric coefficient is given solely in terms of the sum of third moments of the charge density distortions induced by atomic displacements, even for ferroelectric or piezoelectric…
A method for the calculation of the temperature dependence of dielectric and piezoelectric responses, based on the use of a first-principles effective Hamiltonian, is described. Results are presented for the ferroelectric perovskite PbTiO3.…
Pb_1.83Mg_0.29Nb_1.71O_6.39 (PMN) crystallizing in a cubic pyrochlore structure exhibits, as the first dielectrics with pyrochlore structure, typical feature of quantum paraelectrics - its permittivity continuously increases on cooling and…