相关论文: What controls the temperature of a soft mode-drive…
Ta$_2$NiSe$_5$ became one of the most investigated candidate materials for hosting an excitonic insulator ground state. Many studies describe the corresponding phase transition as a condensation of excitons breaking a continuous symmetry.…
This study presents a computational framework to investigate and predict the complicated multiphase properties of eco-friendly lead-free piezoelectric materials, which are crucial for sustainable technological progress. Although their…
The temperature ($T$) as a function of pressure ($P$) phase diagram is reported for the cubic Laves phase compound Au$_2$Pb, which was recently proposed to support linearly dispersing "topological" bands, together with conventional…
Our first-principles computations show that the ground state of PbTiO$_3$ under hydrostatic pressure transforms discontinuously from $P4mm$ to $R3c$ at 9 GPa. Spontaneous polarization decreases with increasing pressure so that the $R3c$…
One account of two-dimensional (2D) structural transformations in 2D ferroelectrics predicts an evolution from a structure with Pnm2$_1$ symmetry into a structure with square P4/nmm symmetry and is consistent with experimental evidence,…
The continuous displacive phase transition in SrTiO$_3$ near $T_c \approx 105$ K features a central elastic peak in neutron scattering investigations at temperatures above $T_c$, i.e., before the corresponding soft phonon mode is overdamped…
We investigate the phase structure and the equation of state (EoS) for dense two-color QCD (QC$_2$D) at low temperature ($T = 40$ MeV, $32^4$ lattice) for the purpose of extending our previous works~\cite{Iida:2019rah, Iida:2022hyy} at…
IV-VI materials are some of the most efficient bulk thermoelectric materials due to their proximity to soft-mode phase transitions, which leads to low lattice thermal conductivity. It has been shown that the lattice thermal conductivity of…
Model materials are precious test cases for elementary theories and provide building blocks for the understanding of more complex cases. Here, we describe the lattice dynamics of the structural phase transition in francisite…
First-principles total-energy calculations are carried out for (001) surfaces of the cubic perovskite ATiO3 compounds PbTiO3, BaTiO3, and SrTiO3. Both AO-terminated and TiO2-terminated surfaces are considered, and fully-relaxed atomic…
Single crystalline bismuth (Bi) is known to have a peculiar electronic structure which is very close to the topological phase transition. The modification of the surface states of Bi depending on the temperature are revealed by…
The behavior of PbTiO$_3$ under uniaxial strains and stresses is investigated from first-principles calculations within density functional theory. We show that irrespectively of the uniaxial mechanical constraint applied, the system keeps a…
Structural phase transitions drive several unconventional phenomena including some illustrious ferroic attributes which are relevant for technological advancements. With this note, we have investigated the structural transition of…
Many dipolar topological structures have been experimentally demonstrated in (PbTiO$_3$)$_n$/(SrTiO$_3$)$_n$ superlattices, such as flux-closure, vortice, and skyrmion. In this work, we employ deep potential molecular dynamics (MD) to…
Perovskite structured materials contain myriad tunable ordered phases of electronic and magnetic origin with proven technological importance and strong promise for a variety of energy solutions. An always-contributing influence beneath…
We have investigated the out-of-plane lattice relaxation related to the ferroelectric transitions in epitaxial BaTiO$_3$ (BTO) films using synchrotron X-ray diffraction. Under either compressive strain or tensile strain, there is evidence…
Piezoelectric PZT solid solutions were studied as a function of pressure and temperature. Moderate pressure is found to induce phase transitions to monoclinic phases (Cm,Cc) for Ti-rich PZT, which are the same ferroelectric phases…
We report neutron inelastic scattering on single crystal 0.68Pb(Mg1/3Nb2/3O3)-0.32PbTiO3 (PMN-0.32PT), a relaxor ferroelectric material that lies within the compositional range of the morphotropic phase boundary (MPB). Data were obtained…
Conventional barocaloric materials typically exhibit limited operating temperature ranges. In contrast, KPF$_6$ has recently been reported to achieve an exceptional all-temperature barocaloric effect (BCE) via pressure-driven phase…
An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this ``inherent…