相关论文: Ferroelectricity of Li-doped silver niobate (Ag,Li…
Halide perovskite semiconductors respond to electric fields in a way that varies across time and length scales. We discuss the microscopic processes that give rise to the macroscopic polarization of these materials, ranging from the optical…
Metal-insulator transitions strongly coupled with lattice were found in Bi1-xLaxNiO3. Synchrotron X-ray powder diffraction revealed that pressure (P ~ 3 GPa, T = 300 K), temperature (T ~ 340 K, x = 0.05), and La-substitution (x ~ 0.075, T =…
Low-dimensional ferroelectricity and polar materials have attracted considerable attentions for their fascinating physics and potential applications. Based on first-principles calculations, here we investigate the stacking modes and polar…
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…
At room temperature, GdMnO3 is a paraelectric and paramagnetic with a distorted perovskite structure of orthorhombic symmetry (space group Pnma). On cooling, it undergoes a phase transition sequence to a magnetic incommensurate phase…
Ferroelectric materials contain a switchable spontaneous polarization that persists even in the absence of an external electric field. The coexistence of ferroelectricity and metallicity in a material appears to be illusive, since…
There has been tremendous research activity in the field of magneto-electric (ME) multiferroics after Kimura et al. [1] showed that antiferromagnetic and ferroelectric order coexist in orthorhom- bically distorted perovskite TbMnO3 and are…
Halide perovskite (HaP) semiconductors are revolutionizing photovoltaic (PV) solar energy conversion by showing remarkable performance of solar cells made with esp. tetragonal methylammonium lead tri-iodide (MAPbI3). In particular, the low…
The recent observation of a ferroelectric-like structural transition in metallic LiOsO$_3$ has generated a flurry of interest in the properties of polar metals. Such materials are thought to be rare because free electrons screen out the…
Micro-Raman spectroscopy and X-ray diffraction have been used to explore the lattice dynamics of Nb-substituted SrBi2(Ta1-xNbx)2O9 (SBTN) crystalline thin films annealed at low temperature, 700oC. It turned out that SrBi2(Ta1-xNbx)2O9 films…
Proximity ferroelectricity is a novel paradigm for inducing ferroelectricity in a non-ferroelectric polar material such as AlN or ZnO that are typically unswitchable with an external field below their dielectric breakdown field. When placed…
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…
We have investigated the magnetic and dielectric properties of orthorhombic Eu$_{1-y}$Y$_y$MnO$_3$ ($0\leq y\leq 0.6$) single crystals without the presence of the 4$f$ magnetic moments of the rare-earth ions. In $y\geq 0.2$, the…
Using first-principles density functional theory we predict a ferroelectric ground state -- driven by off-centering of the magnetic Mn$^{4+}$ ion -- in perovskite-structure BaMnO$_3$. Our finding is surprising, since the competition between…
We report ferroelectric ordering in Ni substituted CaBaCo4O7. Magnetization showed ferrimagnetic transition at 60 K and an additional transition is found ~ 82 K, further, enhanced antiferromagnetic interactions and decrease in saturation…
Layers of perovskites, found in 3D materials, 2D heterostructures, and nanotubes, often distort from high symmetry to facilitate dipole polarisation that is exploitable in many applications. Using density-functional theory calculations,…
The current controversies about the existence of an intermediate 'beta' phase of BiFeO_3 and the high temperature paraelectric 'gamma' phase are resolved by studying the sequence of ferroic transitions in 0.8BiFeO_3-0.2Pb(Fe_1/2Nb_1/2)O_3…
Using first-principles calculations we examine the crystal structures and phase transitions of nitride perovskite LaWN$_3$. Lattice dynamics calculations indicate that the ground-state structure belongs to space group $R3c$. Two competitive…
Despite extensive research interests in perovskite oxides, low energy consumption, non-destructive and maneuverable methods for phase transition in perovskite oxides are still the under its exploration, and the underlying mechanisms remain…
Ferroic transition metal oxides, which exhibit spontaneous elastic, electrical, magnetic or toroidal order, exhibit functional properties that find use in ultrastable solid-state memories to sensors and medical imaging technologies. To…