Related papers: Re-entrant ferroelectricity in liquid crystals
Magnetic and electric properties of a single crystal of La0.7Ca0.3CoO3 have been experimentally studied. The system attains a ferromagnetic spontaneous moment below 170 K and exhibits a re-entrant spin-glass phase below 100 K. In the…
Contrary to conventional wisdom, our purified La2-2xSr1+2xMn2O7 crystals exhibit CE-type orbital and charge order as the low-temperature ground state for a hole doping level h = 0.5. For small deviations from h = 0.5, the high temperature…
Results of detailed investigations of stability of phases in substances with the small difference in the energies of the ferroelectric and the antiferroelectric types of dipole ordering are presented. It is shown that interaction of locally…
We studied dielectric properties of nano-sized liquid water samples confined in polymerized silicates MCM-41 characterized by the porous sizes \sim 3-10nm. We report the direct measurements of the dielectric constant by the dielectric…
A sigma-phase Fe65.9V34.1 alloy was investigated with the AC magnetic susceptibility as a function of temperature, frequency and external magnetic field. An evidence was found that its magnetism shows features characteristic of a reentrant…
The polarization and density modulation associated with antiferroelectric ordering is studied experimentally as a function of temperature in two ferroelectric nematic liquid crystals, the prototypical single compound (DIO) and a commercial…
Liquid crystal materials exhibiting up to three nematic phases are reported. Dielectric response measurements show that while the lower temperature nematic phase has ferroelectric order and the highest temperature nematic phase is apolar,…
We develop a series of approximations to calculate free energy of a polar liquid. We show that long range nature of dipole interactions between the molecules leads to para-electric state instability at low temperatures and to a second-order…
X-ray diffraction experiments were performed on polycrystalline and single-crystal specimens of Ce$_{2}$Fe$_{17}$ at temperatures between 10 K and 300 K. Below $T_{\mathrm{t}}$ = 118$\pm$2 K, additional weak superstructure reflections were…
An axial next-nearest-neighbor XY model is studied as a model of chiral liquid crystals which exhibit many ferro-, ferri- and antiferroelectric tilted smectic phases. Depending on the values of interaction parameters, this model exhibits…
The smectic C (smC) phase represents a unique class of liquid crystal phases characterised by the layered arrangement of molecules with tilted orientations with respect to layer normals. Building upon the real-valued tensorial smectic A…
The orientational and translational order of a thermotropic ferroelectric liquid crystal (2MBOCBC) imbibed in self-organized, parallel, cylindrical pores with radii of 10, 15, or 20 nm in anodic aluminium oxide monoliths (AAO) are explored…
Dielectric spectroscopy of $SrTiO_3$ single crystal over a broad range of microwave frequency using quasi $TE_{m,1,1}$ and quasi $TM_{m,1,1}$ modes reveals crystal asymmetry from typical measurement of $Q$-factor, transmission or frequency…
If a surface stabilized ferroelectric liquid crystal cell is cooled from the smectic-A to the smectic-C phase, its layers thin causing V-shaped (chevron like) defects to form. These create an energy barrier that can prevent switching…
Symmetry-breaking is pivotal for controlling ferroelectric, ferroelastic and/or ferromagnetic functions of materials, which enables applications in sensors, memories, transducers or actuators. Commonly, ferroic phases emerge from descending…
We show that room temperature resistivity of Ba0.5Sr1.5Zn2Fe12O22 single crystals increases by more than three orders of magnitude upon being subjected to optimized heat treatments. The increase in the resistivity allows the determination…
Comprehensive review of investigations of substances with a small difference in the energies of the ferroelectric and antiferroelectric types of dipole ordering is presented. Detailed analysis of the stability of homogeneous phases and…
At variance with structural ferroic phase transitions which give rise to macroscopic tensors coupled to macroscopic fields, criteria defining antiferroelectric (AFE) phase transitions are still under discussion due to the absence of…
SrTiO$_{3}$, a quantum paraelectric, becomes a metal with a superconducting instability after removal of an extremely small number of oxygen atoms. It turns into a ferroelectric upon substitution of a tiny fraction of strontium atoms with…
We use the discrete phenomenological model to study theoretically the phase diagrams in antiferroelectric liquid crystals (AFLCs) as a function of optical purity and temperature. Recent experiments have shown that in some systems the number…