相关论文: Stability of ferroelectric ice

The spin-Peierls instability describes a structural transition of a crystal due to strong magnetic interactions. Here we demonstrate that cold Coulomb crystals of trapped ions provide an experimental testbed in which to study this complex…

Recent neutron diffraction and NMR studies suggest that the incommensurately modulated spin cycloid structure of BiFeO3 is stable down to 4.2 K, whereas DC [M(T)] and AC [\c{hi} ({\omega}, T)] magnetization, and caloric studies have…

The ferroelectric nematic phase (N$_{\text{F}}$) has quickly become the most studied system in liquid crystal research. In this work, we investigate the origin of such polar structure by studying a compound for which the N$_{\text{F}}$…

A structure of spherical white dwarfs is calculated for a non-zero temperature. It is shown that the thermodynamical stability of the white dwarf stars can be described naturally within the concept of the Helmholtz free energy of the…

We extend the Weak Crystallization theory to the case of metallic alloys. The additional ingredient -- itinerant electrons -- generates nontrivial dependence of free energy on the angles between ordering wave vectors of ionic density. That…

Through its dependence on low symmetry crystal phases, ferroelectricity is inherently a property tied to the lower temperature ranges of the phase diagram for a given material. This paper presents conclusive evidence that in the case of…

We have used soft x-ray photoemission electron microscopy to image the magnetization of single domain La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ nano-islands arranged in geometrically frustrated configurations such as square ice and kagome ice…

In the past several years, many important innovations in nanotechnology were made. Today it becomes possible to make nanosize magnetic particles, and development of high storage-density magnetic device is desired. In such a magnetic…

Motivated by recent neutron scattering experiments, we study the ordering of spins in the iron-based superconductors La(O_{1-x}F_x)FeAs, assuming them in proximity to a Mott insulator in the phase diagram. The ground state of the parent…

Earlier investigation of Co_{0.2}Zn_{0.8}Fe_{1.95}Ho_{0.05}O_{4} spinel has shown the existence of "super-ferromagnetic " clusters containing Fe^{3+} and Ho^{3+} ions along with small size clusters of Fe^{3+} ions (Bhowmik et al, J. Magn.…

In the ground state of Ho2Ti2O7 spin ice, the disorder of the magnetic moments follows the same rules as the proton disorder in water ice. Excitations take the form of magnetic monopoles that interact via a magnetic Coulomb interaction.…

A number of crystal structures of water have been `superheated' in Monte Carlo simulations. Two well known models for water were considered; namely the TIP4P model and the SPC/E model. By comparing the fluid-solid coexistence temperature to…

Coarsening dynamics, the canonical theory of phase ordering following a quench across a symmetry breaking phase transition, is thought to be driven by the annihilation of topological defects. Here we show that this understanding is…

We searched for stable crystal structures of YFe$_{12}$ using a crystal structure prediction technique based on a genetic algorithm and first-principles calculations. We obtained two monoclinic $C2/m$ structures as metastable phases that…

Motivated by the observation of partial magnetic order in kagome-based magnets, we study the classical kagome Ising antiferromagnet, known as kagome spin ice, including further-neighbor interactions at zero and finite temperature. While the…

An analysis is presented of the behaviour of muons in the low-temperature state in spin ice. It is shown in detail how the behavior observed in some previous muon experiments on spin ice in a weak transverse field may result from the…

Tb2Ti2O7 is a pyrochlore antiferromagnet that has dynamical spins and only short-range correlations even at 50 mK; the lowest temperature explored so far, which is much smaller than the scale set by the Curie-Weiss temperature T_{CW}~14 K.…

We study Ising pyrochlores by means of Monte Carlo simulations. We cover a set of exchange constants ranging from the frustrated ferromagnetic case (spin-ice) to the fully-ordered "all-in--all-out" antiferromagnet in the dipolar model,…

Recent experimental works reported observation of the {\omega} structure in steel. Here, stability of the {\omega} structure in steel is investigated based on first-principles with special interests in effects of interstitial C atoms. The…

We present the first analytical study of stability loss and evolution of domain structure in inhomogeneous ferroelectric samples for exactly solvable model. The model assumes a short-circuited capacitor with two regions with slightly…