相关论文: Order-disorder transition and alignment dynamics o…
We study the microstructural glass transitions in diblock-copolymer melts using a thermodynamic replica approach. Our approach performs an expansion in terms of the natural smallness parameter -- the inverse of the scaled degree of…
We examine the role of intrinsic chain susceptibility anisotropy in magnetic field directed self-assembly of a block copolymer using \textit{in situ} X-ray scattering. Alignment of a lamellar mesophase is observed on cooling across the…
The dynamic orientational order-disorder transition of clusters consisting of octahedral molecules is formulated in terms of symmetry-adapted rotator functions. The transition from a higher-temperature body-centered-cubic, orientationally…
Common substitutional isovalent semiconductor alloys usually form disordered metastable phases with positive excess formation enthalpies ({\Delta}H). In contrast, monolayer alloys of transition metal dichalcogenides (TMDs) MX2 (M = Mo, W; X…
X-ray diffraction, UV-vis absorption and photoluminescence (PL) spectroscopy have been used to study the well-known order-disorder transition (ODT) to the beta phase in poly(9,9-(di n,n-octyl)fluorene)) (PF8) thin film samples through…
A new mean-field type theory is proposed to study order-disorder transitions (ODT) in block copolymers. The theory applies to both the weak segregation (WS) and the strong segregation (SS) regimes. A new energy functional is proposed…
Recent experiments have highlighted the intrinsic magnetic anisotropy in coil-coil diblock copolymers, specifically in poly(styrene-b-4-vinylpyridine) (PS-b-P4VP), that enables magnetic field alignment at field strengths of a few tesla. We…
It is argued that both transitions observed in 50%-doped manganites, at the N\'{e}el temperature ($T_{\rm N}$) and the so-called charge ordering temperature ($T_{\rm CO}$), are magnetic. $T_{\rm N}$ corresponds to the order-disorder…
The phase transition in a 3D array of classical anharmonic oscillators with harmonic nearest-neighbour coupling (discrete $\phi^4$ model) is studied by Monte Carlo (MC) simulations and by analytical methods. The model allows to choose a…
We have investigated the magnetic properties of Bi0.5Ca0.5MnO3 under ultrahigh magnetic fields by magnetization measurements. This compound shows the metamagnetic transition which indicates the magnetic field induced charge order melting at…
Counterintuitive order-disorder phenomena emerging in antiferromagnetically coupled spin systems have been reported in various studies. Here we perform a systematic effective field theory analysis of two-dimensional bipartite quantum…
We present few ordering mechanisms in block copolymer melts in the coarse-graining approach. For chemically homogeneous or modulated confining surfaces, the surface ordering is investigated above and below the order-disorder temperature. In…
We have determined the nematic-isotropic transition temperature as a function of applied magnetic field in three different thermotropic liquid crystalline dimers. These molecules are comprised of two rigid calamitic moieties joined end to…
We investigate the ordered morphologies occurring in thin-films diblock copolymer. For temperatures above the order-disorder transition and for an arbitrary two-dimensional surface pattern, we use a Ginzburg-Landau expansion of the free…
Using low-energy electron diffraction, we show that the room-temperature $(\sqrt{2}\times\sqrt{2})R45^\circ$ reconstruction of Fe$_3$O$_4$(100) reversibly disorders at $\sim$450 $^\circ$C. Short-range order persists above the transition,…
We consider orientation mechanisms for block copolymers in an electric field. Theoretical and experimental studies have shown that nonuniformity of the dielectric constant gives rise to a preferred orientation of the melt with respect to…
We study the finite temperature phase diagram of the Heisenberg-Kitaev model on a three dimensional hyperhoneycomb lattice. Using semiclassical analysis and classical Monte-Carlo simulations, we investigate quantum and thermal…
We investigate the dynamics of a first order transition when the order parameter field undergoes resonant oscillations, driven by a periodically varying parameter of the free energy. This parameter could be a background oscillating field as…
A theoretical description is presented for low-temperature magnetic-field induced three-dimensional (3D) ordering transitions in strongly anisotropic quantum antiferromagnets, consisting of weakly coupled antiferromagnetic spin-1/2 chains…
Recent experiments discovered an order-disorder transition occuring at low temperatures in large unit 1/1 cell cubic approximants of the stable Cd-based binary alloy quasicrystals. The transition is related to correlations among…