相关论文: Two Displacive Ferroelectric Phase Transitions in …

Our measured dielectric constant and mechanical response of multiferroic BiFeO3 indicate four phase transitions below room temperature. Features correlate with those reported at 50K (from a peak in the zero-field-cooled magnetic…

Spin-phonon interactions are central to many interesting phenomena, ranging from superconductivity to magnetoelectric effects. Yet, they are believed to have a negligible influence on the structural behavior of most materials. For example,…

Dielectric response as a function of frequency for high-permittivity dielectric and ferroelectric materials is discussed emphasizing the dynamic behaviour in the microwave and infrared range. After introducing the usual modelling of the…

The sequence of phase transitions in PbHf0.83Sn0.17O3 has been studied by THz, far infrared and Raman spectroscopies, revealing the complementary behaviour of both, polar and non-polar phonons and their impact on the transition lattice…

The novel ferroelectric-like structural transition observed in metallic LiOsO$_3$ [Y. Shi et al., Nat. Mater. 12, 1024 (2013)], has invoked many theoretical and experimental interests. In this work, we have performed polarized and…

Time-domain THz transmission experiment was performed on a $\rm SrBi_2Ta_2O_9$ film deposited on sapphire substrate. Temperatures between 300 and 923 K were investigated and complex permittivity spectra of the film were determined. The…

Relaxor ferroelectric PbMg_1/3Ta_2/3O_3 ceramics and thin films were investigated by means of broad-band dielectric, time-domain terahertz (THz) and Fourier-transform infrared (IR) spectroscopy in the frequency range 100 Hz - 90 THz at…

The structure and the dielectric properties of Pb(Zn1/3Nb2/3)O3 (PZN) crystal have been investigated by means of high-resolution synchrotron x-ray diffraction (with an x-ray energy of 32 keV) and dielectric spectroscopy (in the frequency…

For CuInP$_2$S$_6$ layered ferrielectric crystal, that is most investigated among wide family of van der Waals ferroics MM$'$P$_2$X$_6$ (M - Cu, Ag; M$'$ - In, Bi, Cr, $\dots$; X - S, Se), by Brillouin spectroscopy the temperature…

Hexagonal YMnO$_3$ is well known for the co-occurrence of ferroelectricity and antiferromagnetism at low temperatures. Using temperature-dependent spectroscopic ellipsometry at an $a$-plane oriented single crystal, we show how the…

We have carried out temperature-dependent x-ray diffraction and Raman scattering experiments on powder $Cs_3Bi_2Br_9$. Trigonal to monoclinic structural transition at around 95 K is discussed and shown to be driven by the softening of the…

We present evidence for a concomitant structural and ferroelectric transformation around $T_S\sim 360$ K in multiferroic BiFeO$_3$/LaAlO$_3$ thin films close to the tetragonal phase. Phonon excitations are investigated by using Raman…

Ultrasonic velocity measurements on the magnetoelectric multiferroic compound CuFeO2 reveal that the antiferromagnetic transition observed at TN1 = 14 K might be induced by an R-3m -> C2/m pseudoproper ferroelastic transition (G. Quirion,…

In-plane temperature dependent dielectric behavior of BiFeO3 (BFO) as-grown thin films show diffuse but prominent phase transitions near 450 (+/-10) K and 550 K with dielectric loss temperature dependences that suggest skin layer effects.…

First-principles electronic structure calculations have been performed for the double perovskite Bi$_2$CoMnO$_6$ in its non-centrosymmetric polar state using generalized gradient approximation plus Hubbard U approach. We find that while Co…

Thin films of (1-x)BiFeO₃-xPbTiO₃ (BF-xPT) with x ~ 0.60 were fabricated on Pt/Si substrates by chemical solution deposition of precursor BF and PT layers alternately in three different multilayer configurations. These…

By using broadband dielectric spectroscopy in the radiofrequency and microwave range we studied the magnetoelectric dynamics in the multiferroic chiral antiferromagnet MnWO$_4$. Above the multiferroic phase transition at $T_{N2} \approx…

The theoretical description of the nanostructured Pb(Fe1/2Ta1/2)x(Zr1/2Ti1/2)1-xO3 (PFTx-PZT(1-x)) and Pb(Fe1/2Nb1/2)x(Zr1/2Ti1/2)1-xO3 (PFNx-PZT(1-x)) intriguing ferromagnetic, ferroelectric and magnetoelectric properties at temperatures…

We report a molecular dynamics study of ab initio quality of the ferroelectric phase transition in crystalline PbTiO3. We model anharmonicity accurately in terms of potential energy and polarization surfaces trained on density functional…

We have investigated the temperature-dependent Raman-active phonons and the magnetic properties of Gd(Co1/2Mn1/2)O3 perovskite ceramics in the temperature range from 40 K to 300 K. The samples crystallized in an orthorhombic distorted…