Related papers: Effective Hamiltonian Methods for Predicting the E…
We report on the synthesis of complex lead-free perovskite-type (1-x)(Ba$_{0.8}$Ca$_{0.2}$)TiO$_3$-xBi(Mg$_{0.75}$W$_{0.25}$)O$_3$ (BCT-xBMW) and (1-x)(Ba$_{0.8}$Ca$_{0.2}$)TiO$_3$-xBi(Mg$_{0.75}$Mo$_{0.25}$)O$_3$ (BCT-xBMM) solid solutions…
We present a molecular dynamics simulation study of CH$_3$NH$_3$PbI$_3$ based on forces calculated from density functional theory. The simulation were performed on model systems having 8 and 27 unit cells, and for a total simulation time of…
Static charge in and on the surface of pyroelectric crystals of LiNbO3 and LiTaO3 in a dilute gas has been shown to ionize gas molecules via electron tunneling. The released electrons and positive ions are focused and accelerated according…
The aim of this article is to decrease the crystallization temperature of the tetragonal perovskite PbTiO3 nanopowders below the PbTiO3 Curie temperature. At the beginning of our study, the calcination temperature was selected based on the…
We have investigated the temperature dependence of the crystal structure of quasi-one-dimensional monoclinic BaIrO$_3$ using X-ray diffraction. Diffraction patterns were measured across a temperature range from 13 K to 300 K, with 5-degree…
SrTiO$_{3}$ is known to be an incipient ferroelectric. It is thought that ferroelectric stability in SrTiO$_{3}$ is suppressed by a delicate competition with quantum fluctuation and antiferrodistortion. The ferroelectric phase can, however,…
The investigation of the structural phase transition in the vicinity of the Curie temperature $T_c$ of LiNb$_{1-x}$Ta$_x$O$_3$ crystals is motivated by the expected combination of advantageous high-temperature properties of LiNbO$_3$ and…
We have performed the calculations of the size effect in the temperature dependence of BaTiO3 nanograin ceramics specific heat and dielectric permittivity. We took into account the distribution of the grain sizes, that exists in any real…
In ferroelectricity, atomic-scale dipole moments interact collectively to produce strong electro-mechanical coupling and switchable macroscopic polarization. Hence, the functionality of ferroelectrics emerges at a solid-solid phase…
Ultra-dense domain walls are increasingly important for many devices but their microscopic properties are so far not fully understood. Here we use molecular dynamic simulations to study the domain wall stability in the prototypical…
A model in which a projectile like fragment can be simply regarded as a remnant after removal of some part of the projectile leads to an excited fragment. This excitation energy can be calculated with a Hamiltonian that gives correct…
PbTiO3 has the highest tetragonal distortion (c/a=1.064) and highest spontaneous polarization among perovskite titanates. But, it is hazardous and hence one needs to reduce Pb content by substituting or reducing Pb content for use in…
Many materials exhibit various types of phase transitions at different temperatures, with many also demonstrating polymorphism. Doping materials can significantly alter their conductivity. In light of this, we have investigated the…
We use molecular dynamics simulations to understand the mechanisms of polarization switching in ferroelectric BaTiO$_3$ achieved with external electric field. For tetragonal and orthorhombic ferroelectric phases, we determine the switching…
A parameterized effective Hamiltonian approach is used to investigate KTaO$_3$. We find that the experimentally observed anomalous dielectric response of this incipient ferroelectric is well reproduced by this approach, once quantum effects…
We propose a pyroelectric energy conversion device that converts heat directly to electricity. In contrast to conventional pyroelectric energy conversion designs, this energy harvesting system is detached from any external power sources,…
We report observation of 90-degree ferroelectric domain structures in transmission electron microscopy (TEM) of epitaxially-grown films of PbTiO3. Using molecular dynamics (MD) simulations based on first-principles effective Hamiltonian of…
Complex electrical permittivity measurements in (1-x)[Pb(Mg1/3 Nb2/3)O3]-xPbTiO3 ceramics for 0.10 x 0.40 were performed in the frequency and temperature range from 1 kHz to 100 kHz and from 15 to 600 K, respectively. Unexpected dielectric…
The ferroelectric to paraelectric phase transition in LiTaO$_3$ and in pure as well as Mg doped LiNbO$_3$ is investigated theoretically by atomistic calculations in the framework of the density functional theory, as well as experimentally…
We report the superconducting properties of single crystals of the intermetallic perovskite-related compound BaBi$_{3}$. The superconducting transition temperature ($T_{c}=5.82$~K) was obtained from heat capacity measurements. Using the…