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Graphical abstract Highlights • Aliphatic polycarbonate based polyurethane forms strong supramolecular structures. • Polyurethane involves three types of physical networks of different thermal stability. • Order–disorder transitions and entanglement formation depend on polymer composition. • Polyurethane is efficiently self-healed. Abstract The aliphatic polycarbonate based polyurethanes (PU) from poly(hexamethylene) carbonate diol (PC), hexamethylenediisocyanate and hexanediol were synthesized, characterized and designed as promising self healing polymers. The symmetrical linear PU structure containing the hexamethylene sequences results in a high degree of ordering and strong superstructures, manifested by a high crystallinity of the PC soft phase and a strong self-assembly of linear hard segments (HS). At the optimum composition, both supramolecular structures percolate resulting thus in the singnificant reinforcement. The PU, undergoing order–disorder transitions, involves three types of physical crosslinks with different thermal stability; PC crystalline phase, HS domains and in addition the entanglements. The structure evolution and reversible sol–gel transition during formation/breaking of the corresponding physical networks was followed by rheology, DSC and FTIR. The kinetics of build-up and stability of physical networks is governed by the content of HSs. The investigation contributed to the understanding and control of the thermal phase transitions of supramolecular structures in aliphatic PCPUs. The strong supramolecular structure undergoing order–disorder transitions, presence of thermally stable entanglement network and excellent mechanical properties make the PCPU suitable as a strong self-healing polymer. Two structural motifs are present: the thermally sensitive structure generating self-healing properties and the shape persistent entanglement network structure preventing the irreversible deformation. The efficient healing and restoration of the original structure and mechanical properties after damage of the polymer were checked by microscopy and tensile testing. [ABSTRACT FROM AUTHOR]

Abstract Phase equilibria and ordered phase regions in the Ni-Mn-Sb system at 700 and 900 °C and the martensite phase region at room temperature were determined mainly by the diffusion triple method. It was confirmed that single-phase region of the ordered bcc phases exists in a wide composition range of a central part at both 700 and 900 °C and that the region is divided into two regions of half-Heusler C1 b and full-Heusler L2 1 at 700 °C, while the C1 b phase is missing at 900 °C. The B2 + L2 1 phase separation was also confirmed in a certain composition range near Ni-50%Mn, and the iso- M s (= RT) line in the L2 1 phase region was also estimated to be located from 12 to 16 at.% Sb. Highlights • Phase diagrams at 700 and 900 °C in the Ni-Mn-Sb ternary system were experimentally determined. • B2 + L 2 1 two-phase region was detected at both 700 and 900 °C. • Critical compositions of L2 1 / C1 b ordering were determined in Ni 2 MnSb/NiMnSb section. • Existing region of martensite phase at room temperature was estimated by diffusion triple. [ABSTRACT FROM AUTHOR]

Highlights • Recent research on dielectric transition and ferroelectricity is overviewed. • Basic concepts and fundamentals of the two properties are introduced. • Structural changes during the phase transitions are discussed. Abstract Structural phase transition in solid-state materials is an underlying factor for emergence and evolution of a number of important physical/chemical properties. In this review, we summarize recent achievements on two types of structural phase transition-associated properties, i.e., dielectric transition and ferroelectricity, in coordination compounds. The basic concepts and fundamentals of structural phase transition and the two properties are briefly introduced. This review aims to reveal the role of the structural phase transitions on bulk properties and afford a perspective on the connections among multiple topics of coordination chemistry from the structural phase transition viewpoint. It would be appealing to researchers in multidisciplinary fields such as coordination chemistry, crystal engineering, supramolecular chemistry, condensed matter physics, responsive materials and molecular machines. [ABSTRACT FROM AUTHOR]

A wide range of mutations in the kinesin motor Kif5A have been linked to a neuronal disorder called hereditary spastic paraplegia (HSP). The position of these mutations can vary, and a range of different motile behaviors have been observed, indicating that the HSP mutants can alter distinct aspects of kinesin mechanochemistry. While focusing on four key HSP-associated mutants, this study examined the structural and dynamic perturbations that arise from these mutations using a series of different computational methods, ranging from bioinformatics analyses to all-atom simulations, that account for solvent effects explicitly. We show that two catalytic domain mutations (R280S and K253N) reduce the microtubule (MT) binding affinity of the kinesin head domains appreciably, while N256S has a much smaller impact. Bioinformatics analysis suggests that the stalk mutation A361V perturbs motor dimerization. Subsequent integration of these effects into a coarse-grained structure-based model of dimeric kinesin revealed that the order-disorder transition of the neck linker is substantially affected, indicating a hampered directionality and processivity of kinesin. The present analyses therefore suggest that, in addition to kinesin-MT binding and coiled-coil dimerization, HSP mutations affecting motor stepping transitions and processivity can lead to disease. [ABSTRACT FROM AUTHOR]

Graphical abstract This work gives our calculation of the magnetization as a function of temperature by the molecular field theory for the DMMn and the chromium-doped DMMn (Cr1, Cr2 and Cr3) close to phase transitions. Our calculated M (T) values are compared with the experimantal data from the literature. We also analyze the temperature and the field dependence of the magnetization M (T , H) by using the literature data through the power-law formula. This analysis is carried out for the nearly second order transition in DMMn and the chromium-doped DMMn. This method of calculating magnetization and its analysis motivate describe ferromagnetic transitions in those compounds studied and also in similar structures in the metal organic frameworks (MOFs). Abstract We study the temperature and field dependence of the magnetization M (T , H) for the order–disorder transition in DMMn and the chromium-doped DMMn close to T C. By analyzing the experimental data for M (T , H) from the literature according to the power-law formula, values of the critical exponent (β) and the critical isotherm (δ) are deduced and also, the temperature dependence of magnetization M (T) is calculated from the molecular field theory for those compounds. Our calculated M (T) and the values of β and δ from the analysis of M (T , H) indicate that DMMn and chromium-doped DMMn undergo nearly second order transition. [ABSTRACT FROM AUTHOR]

With supersaturated carbon atoms ordering in the preferential octahedral sites of α-Fe lattice, the martensite formed in medium and high carbon steels exhibit a unique structural feature, tetragonality. In this letter, we reported anomalous nontetragonality of martensite in carbon steels by deforming quenched martensite, indicating that the disordering of interstitial carbon atoms in α-Fe lattice occurs under mechanical deformation. This order-disorder transition of interstitial carbon atoms in carbon steels provides solid experimental evidences of the prediction based on microscopic elasticity theory. [ABSTRACT FROM AUTHOR]

The formation of the Pt-enriched layer (Pt skin layer) formed at the surface of the ordered and disordered Pt-Co alloy specimens by a dealloying treatment and its corrosion resistance under potential cycling in sulfuric acid were examined to clarify the dissolution behavior of the Pt skin layer in polymer electrolyte fuel cell-operating conditions. The ordered and disordered Pt-Co specimens were obtained by heat treatment at 1073 and 1473 K, respectively. Co at the alloy surfaces dramatically dissolved in an early phase of the dealloying treatment in naturally aerated 0.5 M H2SO4 at 298 K, and Pt skin layers were formed. Pt skin layers ca. 2 monolayer in thickness were formed on the Pt-Co alloy specimens by the dealloying treatment in 0.5 M H2SO4. The cyclic voltammetry measurements of the Pt-Co specimens showed the existence of Pt skin layers after the dealloying treatment and the inhibition of the Pt oxide formation on the Pt skin layers. The Pt oxide formation for ordered Pt-Co was more suppressed than that for the disordered Pt-Co. The Pt skin layers on the Pt-Co specimens exhibited a higher corrosion resistance than pure Pt, and the dissolution of the Pt skin layer for ordered Pt-Co was more inhibited than that for disordered Pt-Co under potential cycling in the potential range of 0.6-1.4 V in 0.5 M H2SO4 (dissolution test). A thin, continuous Pt skin layer remained at the surface of the ordered Pt-Co specimen after the dissolution test. The formation of a uniform Pt skin layer seems to provide high oxidation resistance to the surface, leading to high corrosion resistance.The dissolution of Pt skin layer for the ordered Pt-Co was highly suppressed compared with that for the disordered Pt-Co and pure Pt. The suppression of Pt-O formation seems to be the main reason for the high corrosion resistance. The formation of a thin and continuous Pt skin layer is important to prevent the dissolution of Pt. [ABSTRACT FROM AUTHOR]

Prostate-associated gene 4 (PAGE4) is an intrinsically disordered protein implicated in prostate cancer. Thestress-response kinase homeodomain-interacting protein kinase 1 (HIPK1) phosphorylates two residues in PAGE4, serine 9 and threonine 51. Phosphorylation of these two residues facilitates the interaction of PAGE4 with activator protein-1 (AP-1) transcription factor complex to potentiate AP-1's activity. In contrast, hyperphosphorylation of PAGE4 by CDC-like kinase 2 (CLK2) attenuates this interaction with AP-1. Small-angleX-ray scattering and single-molecule fluorescence resonance energy transfer measurements have shown that PAGE4 expands upon hyperphosphorylation and that this expansion is localized to its N-terminal half. To understand the interactions underlying this structural transition, we performed molecular dynamics simulations using Atomistic AWSEM, a multi-scale molecular model that combines atomistic and coarse-grained simulation approaches. Our simulations show that electrostatic interactions drive transient formation of an N-terminal loop, the destabilization of which accounts for the dramatic change in size upon hyperphosphorylation. Phosphorylation also changes the preference of secondary structure formation of the PAGE4 ensemble, which leads to a transition between states that display different degrees of disorder. Finally, we construct a mechanism-based mathematical model that allows us to capture the interactions ofdifferent phosphoforms of PAGE4 with AP-1 and its downstream target, the androgen receptor (AR)—a key therapeutic target in prostate cancer. Our model predicts intracellular oscillatory dynamics of HIPK1-PAGE4, CLK2-PAGE4, and AR activity, indicating phenotypic heterogeneity in an isogenic cell population. Thus, conformational switching of PAGE4 may potentially affect the efficiency of therapeutically targeting AR activity. [ABSTRACT FROM AUTHOR]

Using in-situ transmission electron microscopy and atomistic simulations, we report atomic-scale observations of segregation-induced structure changes in the surface and subsurface region of a Cu(Au) solid solution in both reductive and oxidative environments. In a H 2 atmosphere, Au segregation induces the formation of a two-atomic-layer thick ordered surface alloy with an L1 0 terminated surface layer. By switching to an O 2 atmosphere, the outermost surface develops into an Au-missing row reconstruction and simultaneously the second layer experiences an order-disorder transition via intralayer atomic exchanges. The chemical disordering then propagates to the outermost surface, driven by oxygen-adsorption induced Cu surface segregation. This transforms the L1 0 missing-row reconstruction into a non-reconstructed, oxygenated surface. These observations provide a mechanistic detail regarding the evolution of the surface and subsurface of this alloy in response to environmental stimuli, and are relevant to a wide range of technologically relevant processes. [ABSTRACT FROM AUTHOR]

Bi 2 (Zn 1/3 Nb 2/3 ) 2 O 7 ceramics were synthesized using conventional solid-state reaction. The effect of densification annealing treatments on microstructures and microwave dielectric properties of Bi 2 (Zn 1/3 Nb 2/3 ) 2 O 7 ceramics have been investigated. The ordered of B-site zirconolite structures were obtained after a long-time annealing. The order-disorder transition contributes to enhance the microwave dielectric properties of Bi 2 (Zn 1/3 Nb 2/3 ) 2 O 7 ceramics. The ceramics sintered at 980 °C exhibit a large permittivity of 75 and a Qf value of 3000 GHz. The most efficient annealing treatment which induced a≈100% improvement of Qf value was obtained in the samples annealed at 890 °C for 24 h, while the permittivity remain stable. As the annealing temperature increased to 930 °C, the Qf value abruptly decreased. The microwave dielectric properties of Bi 2 (Zn 1/3 Nb 2/3 ) 2 O 7 ceramics are affected by the enhancement of cation order and the reduction of crystal defect. An excellent microwave dielectric properties Qf ≈ 6300 GHz, ε ≈ 76 and τ f  ≈ 189 ppm/°C was obtained when the ceramic was annealed at 890 °C for 24 h. [ABSTRACT FROM AUTHOR]

The relation between metal order-disorder and magnetic properties in the solid solution Hf 1– x Ti x MnSb 2 (0 ≤  x  ≤ 1) with the NiAs structure is investigated. The synchrotron X-ray diffraction studies have revealed that two-dimensional (2D) metal-ordered structure in HfMnSb 2 persists up to x  = 0.15, though its degree of metal order decreases with x . Although the NiAs-like phase is not formed for 0.2 ≤  x  ≤ 0.3, a metal disordered phase appears for x  ≥ 0.4. A conical spin order is only found in the metal-ordered region and is fairly robust against partial cation disorder, while the completely metal-disordered region is a ferromagnetic state, providing firm evidence that the presence/absence of metal order essentially defines the ground state. Neutron depolarization measurement for HfMnSb 2 suggests possible successive phase transitions. [ABSTRACT FROM AUTHOR]

Order-disorder transitions of a vortex lattice transfer type-II superconductors from a low critical current state to a high one. The similar transition between different current states can be caused by electromagnetic granularity. A sigmoid curve is proposed to describe the corresponding peak in a field dependence of the macroscopic critical density. Using the extended critical state model, analytic expressions are obtained for the field dependencies of the local critical current density, the depth of equilibrium surface region, and the macroscopic critical current density. The expressions are well fit to published data. [ABSTRACT FROM AUTHOR]

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Refractory high-entropy alloys (RHEAs) are regarded as promising candidates of the next generation superalloys, mainly benefitting from the high strength at high temperatures. However, they are not competitive in lightweight, room-temperature ductility, and corrosion resistance compared with other superalloys. In this work, novel Ti 1.6 ZrNbAl 0.4- x V x (x = 0, 0.2, 0.4) lightweight RHEAs (LRHEAs) were fabricated and systematically investigated. The substitution of V for Al promoted strength-ductility synergy and ameliorated the corrosion resistance of the current LRHEAs. More specifically, an increase in V content caused a phase transformation from a BCC + B2 dual phase structure to a single BCC phase structure and a reduction of grain sizes. Mechanical tests demonstrated that the Ti 1.6 ZrNbAl 0.2 V 0.2 LRHEA possesses a high yield strength of ∼806 MPa and a moderate tensile ductility of ∼13.2%, which is attributed to synergetic strengthening from grain refinement and solid solution strengthening induced by V addition. In addition to the homogenous phase structure and fine grain sizes, excellent anti-corrosion properties of Ti 1.6 ZrNbAl 0.2 V 0.2 LRHEA were also attributed to the doping effect of V, leading to the formation of a high content of corrosion-protective products. Our findings provide a new paradigm for achieving such outstanding combinations in LRHEAs. • Novel Ti 1.6 ZrNbAl 0.4- x V x lightweight refractory high-entropy alloys (LRHEAs) were developed and fabricated. • Mechanical properties and corrosion behavior of the LRHEAs were systematically investigated and analyzed in details. • Excellent combination of mechanical properties and corrosion resistance in LRHEAs were achieved. [ABSTRACT FROM AUTHOR]

Bulk samples of kesterite (Cu2ZnSnS4, CZTS) were produced by cold-pressing and sintering of CZTS powders obtained via reactive ball-milling. An increase in the Seebeck coefficient of more than 100 μV/K, almost doubling the expected value, is noticed around a temperature of 260 °C. As pointed out by thermal analyses, this is due to a second order transition of kesterite from an ordered I-4 to a disordered I-42m crystal structure. Conversely to what happens for solar cell materials, where the transition is considered to be detrimental for the performance, it appears to be beneficial for the thermoelectric Seebeck coefficient, suggesting that higher crystal symmetry and cation-disorder due to the transition lead to thermopower enhancement.

The reaction of Bi, BiCl3, and TlCl in the ionic liquid [BMIm]Cl·4AlCl3 (BMIm = 1-n-butyl-3-methylimidazolium) at 180 °C yielded air-sensitive black crystals of (Bi8)Tl[AlCl4]3. X-ray diffraction on single crystals at room temperature revealed a structure containing [ Tl ( AlCl 4 ) 3 ] ∞ 1 2 − strands separated by isolated Bi82+ square antiprisms. The thallium(I) ion is coordinated by twelve Cl− ions of six [AlCl4]− groups, resulting in a chain of face-sharing [TlCl12]11− icosahedra. The Bi82+ polycation is disordered, simulating a threefold axis through its center and overall hexagonal symmetry (space group P63/m). Slowly cooling the crystals to 170 K resulted in increased order in the Bi8 cluster orientations. An ordered structure model in a supercell with a’ = 2a, b’ = 2b, c’ = 3c and the space group P65 was refined. The structure resembles a hexagonal perovskite, with complex groups in place of simple ions.

By combining poly(1,4-isoprene) (PI) with poly(ferrocenylmethyl methacrylate) (PFMMA) in a diblock copolymer structure by means of anionic polymerization we obtained narrowly dispersed PI- b -PFMMA copolymers with molecular weight ranging from 13000 to 62000 g/mol. The products were stable up to 228 °C, according to thermal gravimetry, which allowed us to further investigate their viscoelastic and X-ray scattering properties at elevated temperature by rheology and SAXS, respectively. For PI- b -PFMMA with total molecular weight 13400 g/mol a phase transition at 105 °C was identified leading to the segmental mixing at T > 105 °C and microphase separation at T < 105 °C. The microphase separated morphology acquired hexahonally packed cylinder (HEX) microstructure in bulk. The explanation of the ordered HEX morphology was derived from a quantification of the thermodynamic immiscibility between PI and PFMMA segments via random phase approximation theory yielding generally accepted dependency of the Flory-Huggins interaction parameter ( χ ) on temperature. [ABSTRACT FROM AUTHOR]

Static and dynamic properties of diblock and triblock copolymer melts are simulated over a wide range of temperatures in vicinity of the order-disorder transition and also in the strong segregation regime. Dynamic Monte Carlo method, known as the Cooperative Motion Algorithm, is used with a parallel tempering scheme in order to determine a variety of physical properties. Structure factors are of particular interest since they can be directly related to Small Angle X-ray Scattering data. We also report energy, specific heat, mean-squared end-to-end distance, and the translational diffusion coefficient. Moreover, we determine order-disorder temperatures and investigate the behavior of the melts at low temperatures. We show that the finite size effects can be associated with the spatial reorientations of lamellae. Furthermore, we confirm the existence of a sharp low-temperature peak in specific heat, which we relate to the transition from a state with the diffused domain interface to a state with the sharp domain interface. The chain length dependence of the order-disorder temperatures and the interfacial smoothing temperatures are also presented. Below order-disorder transition temperature a significant loss of the chain mobility is observed, as indicated by an abrupt decrease of the diffusion coefficient. [ABSTRACT FROM AUTHOR]

A 1000 °C isothermal phase diagram in the total composition range of the Fe-Co-Si ternary system is constructed featuring the interconnected ε-(Fe,Co)Si, large bcc-structure (αFe), and fcc-structure (γFe,αCo) phases. In addition, a vertical magnetic plus ordering transition phase diagram of Fe 80- x Co x Si 20 alloys is also constructed. It is shown that the magnetic transition (D0 3 ferro./para. ) temperature increases with the Co concentration and reaches a maximum value (845 °C) at 50 at. % Co in the investigated Fe 80- x Co x Si 20 alloys. Meanwhile, the B2/D0 3 ordering transition temperature versus Co content dependence exhibits an initial slight rise followed by a gradual decrease to ∼67 at. % Co. Furthermore, a fcc/bcc martensitic transformation was revealed in several Co-rich ternary alloys under study. The resulting lath martensitic microstructures of the studied alloys include numerous twins and dislocations defects, revealing a similarity with the FeNi-based alloy system. [ABSTRACT FROM AUTHOR]

The crystal structure and dielectric properties of TiO2-modified Ca[(LiNb)Sn]O microwave ceramics are investigated in the present paper. The crystal structure is probed by XRD patterns and their Rietveld refinement, results show that a single perovskite phase is formed in TiO2-modified Ca[(LiNb)Sn]O ceramics with the crystal structure belonging to the orthorhombic Pbnm 62 space group. Raman spectra results indicate that the -site order-disorder structure transition is a key point to the dielectric loss of TiO2-modified Ca[(LiNb)Sn]O ceramics at microwave frequencies. After properly modified by TiO2, the large negative temperature coefficient of Ca[(LiNb)Sn]O ceramic can be compensated and the optimal microwave dielectric properties can reach = 25.66, = 18,894 GHz and TCF = −6.3 ppm/C when sintered at 1170C for 2.5 h, which manifests itself for potential use in microwave dielectric devices for modern wireless communication. [ABSTRACT FROM AUTHOR]

Involving supramolecular chemistry in self-assembling block copolymer systems enables design of complex macromolecular architectures that, in turn, could lead to complex phase behavior. It is an elegant route, as complicated and sensitive synthesis techniques can be avoided. Highly grafted double-comb diblock copolymers based on symmetric double hydrogen bond accepting poly(4-vinylpyridine)- block-poly( N-acryloylpiperidine) diblock copolymers and donating 3-nonadecylphenol amphiphiles are realized and studied systematically by changing the molecular weight of the copolymer. Double perpendicular lamellae- in-lamellae are formed in all complexes, independent of the copolymer molecular weight. Temperature-resolved measurements demonstrate that the supramolecular nature and ability to crystallize are responsible for the formation of such multiblock-like structures. Because of these driving forces and severe plasticization of the complexes in the liquid crystalline state, this supramolecular approach can be useful for steering self-assembly of both low- and high-molecular-weight block copolymer systems. [ABSTRACT FROM AUTHOR]

Block copolymers have been extensively studied due to their ability to spontaneously self-organize into a wide variety of morphologies that are valuable in energy-, medical-, and conservation-related (nano)technologies. While the phase behavior of bicomponent diblock and triblock copolymers is conventionally governed by temperature and individual block masses, it is demonstrated here that their phase behavior can alternatively be controlled through the use of blocks with random monomer sequencing. Block random copolymers (BRCs), i.e., diblock copolymers wherein one or both blocks are a random copolymer comprised of A and B repeat units, have been synthesized, and their phase behavior, expressed in terms of the order-disorder transition (ODT), has been investigated. The results establish that, depending on the block composition contrast and molecular weight, BRCs can microphase-separate. We also report that large variation in incompatibility can be generated at relatively constant molecular weight and temperature with these new soft materials. This sequence-controlled synthetic strategy is extended to thermoplastic elastomeric triblock copolymers differing in chemistry and possessing a random-copolymer midblock. [ABSTRACT FROM AUTHOR]

Schizophyllan and scleroglucan are water-soluble polysaccharides having repeating units consisting of three β-1,3-linked glucose residues in the main chain and a single β-1,6-linked glucose residue as the side chain. This polysaccharide dissolves as a triple helix in an aqueous solution and shows a cooperative order-disorder transition between the side chain and solvent molecules while retaining the triple helical conformation. Periodate and subsequent chlorite oxidations selectively modify the side chain glucose to provide the corresponding dicarboxylate units. Optical rotation measurements and differential scanning calorimetry were performed on carboxylated schizophyllan/scleroglucan (‘sclerox’) samples to investigate the effects of the degree of carboxylation on the order-disorder transition in deuterium oxide with 0.1 M NaCl. The transition curves for the sclerox samples are strongly dependent on the degree of carboxylation. The modified side chains cannot take the ordered structure, resulting in a reduction of the transition enthalpy. The transition temperature for carboxylated schizophyllan becomes lowered and the transition curve broadens with increasing the degree of carboxylation. The permanent disordered units are included in a trimer by the carboxylation to inhibit a long sequence of the ordered units. [ABSTRACT FROM AUTHOR]

In this study the influence of low-temperature structural ordering in absorber material to the performance of Cu 2 ZnSnS 4 (CZTS) monograin layer (MGL) solar cells was investigated. The shift of peak position in low temperature and room temperature photoluminescence measurements was used to estimate the Cu-Zn disorder level in CZTS monograin powders. The degree of Cu-Zn ordering was changed by using different cooling times after annealing CZTS powders in S atmosphere at 740 °C and by additional annealing at temperatures below critical temperature ( T c ~ 260 °C) for different time periods. Current-voltage measurements revealed that the low-temperature thermal treatments resulting in increased ordering of CZTS absorber material had significant impact on the MGL solar cell characteristics, mostly, the values of open circuit voltage ( V oc ) were increased. The highest V oc of 784 mV was measured for the solar cell based on the powder that was cooled from 740 °C to room temperature for 5 min followed by annealing at 150 °C for 24 h. Optimal conditions for low-temperature annealing to improve CZTS MGL solar cells' performance were found to be 4 h at 150 °C. These improvements resulted in CZTS MGL solar cell power conversion efficiency of 9.1% (active area). [ABSTRACT FROM AUTHOR]

Exact graft copolymer (EGC) is a type of copolymer with precisely defined molecular parameters, including the number of grafts per molecule ( n), the length of the grafts ( lg), and the separation distance between the junction points (ε) in the backbone. In the present study, the phase structure of the EGC composed of poly(2-vinyl pyridine) backbone and polystyrene graft with n = 2 and n = 3 under fixed ε and lg is systematically investigated to seek a general understanding on the effect of the graft architecture on the domain spacing of the microphase-separated structure and the order-disorder transition temperature ( TODT). It is found that the TODT associated with the fluctuation-induced ODT of the EGC increases with increasing n due to the increase of the total molecular weight. Nevertheless, the domain spacing does not exhibit a monotonic change with n, as the EGC with n = 2 shows the largest domain spacing compared with that of EGC with n = 3 and the corresponding linear diblock copolymer. The experimental observation on the domain spacing is explained by a thermodynamic model considering the packing mode of the constituting chains under the junction constraint. [ABSTRACT FROM AUTHOR]

In this work the Cu/Zn order-disorder transition in Cu 2 ZnSnS 4 kesterites on Wyckoff positions 2c and 2d was investigated by a structural and electronic analysis in theory and experiment. For experimental investigations stoichiometric samples with different Cu/Zn order, annealed in the temperature range of 473–623 K and afterwards quenched, were used. The optical gaps were determined using the Derivation of Absorption Spectrum Fitting (DASF) method. Furthermore, the order-disorder transition was examined by DFT calculations for a closer analysis of the origins of the reduced band gap, showing a good agreement with experimental data with respect to structural and electronic properties. Our studies show a slight increase of lattice parameter c in the kesterite lattice with increasing disorder. Additionally, a reduced band gap was observed with increasing disorder, which is an effect of newly occurring binding motifs in the disordered kesterite structure. [ABSTRACT FROM AUTHOR]

The phase boundary between B2 ordered and disordered phases in the Fe-rich region of the Fe-Si binary system is calculated by Cluster Variation Method (CVM). The configurational entropy is formulated within the tetrahedron approximation of CVM, and the internal energy is derived by Cluster Expansion Method (CEM) operated on a set of total energies calculated by DFT. The Debye Gruneisen model is employed to introduce the vibrational effect. The second order transition for the B2 order-disorder transition is confirmed, which is in agreement with the published phase diagram data and the results of previous CALPHAD calculations. The calculated transition temperature in the present study is higher around the stoichiometric composition and lower in the Fe-rich region compared to the experimental transition temperature. One reason for this overestimation and underestimation of the transition temperature may stem from the facts that the local atomic displacement and wide range atomic correlations are not considered in the present study. The transition temperature is also determined using Thermo-Calc software with the SSOL4 database. The transition temperature obtained by Thermo-Calc calculations accurately reproduces the experimental results. Hence, it is considered that the interaction parameters and the ordering parameters of CALPHAD free energy implicitly include the contributions of short range ordering and local atomic displacement. [ABSTRACT FROM AUTHOR]

Folded proteins show a high degree of structural order and undergo (fairly constrained) collective motions related to their functions. On the other hand, intrinsically disordered proteins (IDPs), while lacking a well-defined three-dimensional structure, do exhibit some structural and dynamical ordering, but are less constrained in their motions than folded proteins. The larger structural plasticity of IDPs emphasizes the importance of entropically driven motions. Many IDPs undergo function-related disorder-to-order transitions driven by their interaction with specific binding partners. As experimental techniques become more sensitive and become better integrated with computational simulations, we are beginning to see how the modest structural ordering and large amplitude collective motions of IDPs endow them with an ability to mediate multiple interactions with different partners in the cell. To illustrate these points, here, we use Prostate-associated gene 4 (PAGE4), an IDP implicated in prostate cancer (PCa) as an example. We first review our previous efforts using molecular dynamics simulations based on atomistic AWSEM to study the conformational dynamics of PAGE4 and how its motions change in its different physiologically relevant phosphorylated forms. Our simulations quantitatively reproduced experimental observations and revealed how structural and dynamical ordering are encoded in the sequence of PAGE4 and can be modulated by different extents of phosphorylation by the kinases HIPK1 and CLK2. This ordering is reflected in changing populations of certain secondary structural elements as well as in the regularity of its collective motions. These ordered features are directly correlated with the functional interactions of WT-PAGE4, HIPK1-PAGE4 and CLK2-PAGE4 with the AP-1 signaling axis. These interactions give rise to repeated transitions between (high HIPK1-PAGE4, low CLK2-PAGE4) and (low HIPK1-PAGE4, high CLK2-PAGE4) cell phenotypes, which possess differing sensitivities to the standard PCa therapies, such as androgen deprivation therapy (ADT). We argue that, although the structural plasticity of an IDP is important in promoting promiscuous interactions, the modulation of the structural ordering is important for sculpting its interactions so as to rewire with agility biomolecular interaction networks with significant functional consequences.

The order-disorder phase transition in the Nd x Zr 1−x O 2−0.5x system is studied by complementary techniques which include wet chemical synthesis of a series of compositions with various Nd/Zr ratios with the final annealing at 1873 K, X-ray diffraction, oxide melt solution calorimetry and ab initio thermodynamic modeling. Our structural data indicate the transition from ordered to disordered pyrochlore at x ∼0.31 at a temperature of 1873 K. Our calorimetric data show a transition enthalpy of ∼30 kJ/mol, which corresponds to an entropy of disordering of ∼16 J/K/mol. The latter value is significantly smaller than the configurational entropy of transition computed under the assumption of complete disorder in a fluorite phase, indicating a substantial degree of order remaining in the fluorite phase at the temperature of synthesis. The considered phases are computed ab initio using a series of special quasi-random structures that emulate the complete or partial disorder. The results of our calculations and thermodynamic modeling are in good agreement with the measured lattice parameters, the Nd content at the order-disorder transition, and the measured formation and transformation enthalpies. Thus our combined experimental and modeling results provide valuable insight into the disordering of this pyrochlore phase and of other pyrochlore materials. [ABSTRACT FROM AUTHOR]

ABSTRACT Narrowly dispersed diblock copolymers containing poly(methyl methacrylate) [PMMA] or poly(nonafluorohexyl methacrylate) [PF9MA] as the first block and poly(ferrocenylmethyl methacrylate) [PFMMA] as the second block, were prepared by anionic polymerization for the first time. Disordered bulk morphologies in the case of PMMA- b-PFMMA were observed and explained in terms of low Flory-Huggins interaction parameter ( χ ≤ 0.04). In the case of PF9MA- b-PFMMA hexagonally packed cylinder morphology (HEX) was substantiated from TEM and SAXS observations. Furthermore, high incompatibility between PF9MA and PFMMA blocks allowed for the formation of well-ordered ferrocene containing cylinders on silica substrate upon exposure of the thin films to a saturated solvent vapor. It was shown that the cylinder orientation, parallel or perpendicular to the surface, could easily be controlled by appropriate choice of the solvent and without the need for preliminary surface modification, for example by means of grafted brush layer. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 495-503 [ABSTRACT FROM AUTHOR]

The effects of blockiness and compositional/sequential polydispersity on the order-disorder transition of random block copolymers are studied using a segment model of random block copolymers. Specifically, the copolymers are randomly assembled from a collection of equal-length 'segments,' while the characteristics of the segments are chosen according to the nature of the polydispersity. The phase behavior of the model system is examined using the random phase approximation. The critical points of the system are calculated over a range of blockiness and polydispersity for a variety of segment models. It is observed that the critical value of the Flory-Huggins parameter χ, above which the homogeneous phase becomes unstable, is inversely proportional to the blockiness. Furthermore, it is found that sequential and compositional dispersity decreases the critical value of χ, but that the effect of sequential dispersity is much weaker. At sufficiently large compositional dispersity, the random block copolymers can undergo macrophase separation. In this region of phase space, the critical point is entirely determined by the compositional polydispersity. [ABSTRACT FROM AUTHOR]

Organic thermoelectric materials have gained a trajectory in recent years given its advantages of processability, low cost and flexibility. In this paper, polymer electrolyte liquid crystal (PELC) mixtures composed of polyvinyl alcohol, potassium iodide, and 4-Cyano-4'-pentylbiphenyl (5CB) liquid crystal are fabricated, the 5CB acts as a ‘temperature switch’, i.e., a strong correlation between the thermoelectric properties and the transition from Ne-Iso transition of the 5CB, is observed. The electrical conductivity and Seebeck coefficient of the PELC mixtures both decrease above the Ne-Iso transition temperature. This thermoelectric behavior is discussed in terms of the carrier concentration, carrier mobility, and order-disorder transition. [ABSTRACT FROM AUTHOR]

Phase equilibria of the Al–Co–Ni system is extremely useful for understanding phase behavior of AlNi 3 -based L1 2 phases, regarding its attractive properties, such as high-temperature oxidation resistance and corrosion resistance, high hardness and strength. In the present work, all the experimental data about the phase equilibria and thermodynamic properties of the Al–Co–Ni system were critically evaluated, and a thermodynamic description for this system over the whole composition and temperature ranges was obtained. Most importantly, the ordered/disordered transition between fcc_A1 and L1 2 phases was described using a four-sublattice (4SL) model. Based on the crystallographic and experimental data, three stable ternary intermetallic phases were described using sublattice model. Two of them were treated as semi-stoichiometric compounds with homogeneity ranges for Co and Ni, and the other one was treated as a stoichiometric compound. The other phases were described by using substitutional solution model. The present work provides a more complete and accurate thermodynamic description compared with previous ones. A reasonable agreement was obtained between calculations and experimental data in the ternary system. The occupancy behavior of Co in AlNi 3 is thermodynamically predicted, and the computed occupancy shows a much better fit to the experimental data than previous first-principles calculations. In addition, the composition range of the Co + AlNi 3 two-phase region, concerning a new type of composite binder for cemented carbides, was found to shift to the Co-rich side with the decrease of the temperature. [ABSTRACT FROM AUTHOR]

A Rietveld analysis of neutron powder diffraction patterns obtained in situ during temperature scans shows that Fe 2 VAl crystallizes at room temperature in the fully ordered L 2 1 structure and transforms at 1080 °C and at 1190 °C into partially disordered B 2 and fully disordered A 2 variants respectively. The low temperature stability of the L 2 1 structure as well as the two high temperature L 2 1 → B 2 → A 2 transitions are theoretically predicted by a combination of ab-initio (electronic structure and phonons) and thermodynamic calculations performed on special quasi-random structures. Pronounced cold work effects and the pre-transitional antisite defects which are observed respectively at 25 °C under mechanical stress and at high temperature (above 800 °C), appear to be generic effects in the family of Heusler alloys. [ABSTRACT FROM AUTHOR]

The synthesis of multicomponent perovskites ( Ln 0.25 Mn 0.75 )(Al 0.25 Ti 0.75 )O 3 ( Ln =La, Pr, Nd, Sm, Gd, Tb, Dy, Y) have been investigated using a high-pressure and high-temperature (6 GPa, 1175 °C) technique. When Ln 3+ is larger La 3+ , Pr 3+ , Nd 3+ , the A-site ordered perovskites, Ln Mn 3 (Al 0.25 Ti 0.75 ) 4 O 12 in Im -3, have been successfully synthesized. The A-site partially disordered one, (Sm 0.80 Mn 0.20 )(Sm 0.07 Mn 0.93 ) 3 (Al 0.25 Ti 0.75 ) 4 O 12 is also obtained. In the case of smaller Gd 3+ , Tb 3+ , Dy 3+ , we have obtained no single phase but two decomposed perovskite phases. When Ln 3+ is much smaller Y 3+ , it is crystallized as an A-site disorder one in Pnma . The Rietveld structural refinements of the A-site ordered and partially disordered perovskites indicate that the tilting of (Al/Ti)O 6 octahedrons for the A-site ions ordering is correlated with the (Al/Ti)–O and Ln –O bond lengths to optimize the coordination of the A - and A′ -sites. The phase stability of the A-site ordered perovskites is discussed from the viewpoint of this correlation. [ABSTRACT FROM AUTHOR]

Two distinct evolutionary processes of secondary γ′ precipitates in a Ni-based single crystal superalloy were revealed by means of Cs-corrected high-resolution transmission electron microscopy (HRTEM) and corresponding X-ray energy dispersive spectroscopy analyses. Upon creep testing at elevated temperatures, it was determined that large quantities of secondary γ′ precipitates were formed. The precipitates were found to select two distinctive forms and routes: one randomly dispersed in the γ matrix (2nd γ′ γ ), and the other formed at nodes of dislocation networks (2nd γ′ d ) in regular arrays. These two types of secondary γ′ precipitates exhibited different evolutionary morphologies and mechanisms. The 2nd γ′ γ precipitates progressively evolved in shape from spherical to cuboidal and then to butterfly-like shapes, and the mean size also increased gradually from 11 nm to 34 nm. The 2nd γ′ d precipitates exhibited stable cuboidal morphology and a mean size of ∼30 nm. These differences are attributable to the different element transport conditions for the two types of precipitates, i.e., an uphill diffusion for the 2nd γ′ γ precipitates and a dislocation network pipe transportation for the 2nd γ′ d precipitates. The 2nd γ′ γ precipitates show severe segregation of γ′-rich elements of Ni and Al and deficiency of γ′-poor elements of Cr compared with the 2nd γ′ d precipitates. [ABSTRACT FROM AUTHOR]

Strontium succinate, an active pharmaceutical ingredient against osteoporosis, exhibits two polymorphs related by a reversible order-disorder transformation at about 50 °C. However, during the industrial crystallization process, the transition from the high-temperature form towards the low-temperature form was partially inhibited, leading to a mixture of phases at room temperature. The stressful character of the industrial process as demonstrated by in situ X-ray diffraction and Raman analyses led to defects, constraints, and a coarse mosaicity within crystals. Moreover, thermogravimetric analyses revealed that a non-negligible amount of water was trapped inside the crystalline solid. The combination of these two factors (stressful crystallization and trapped water) could be at the origin of the partial blockage of the transition. [ABSTRACT FROM AUTHOR]

Compounds in the pyrochlore system Ho 2 ( Zr y Ti 1− y ) 2 O 7 exhibit an order-disorder transition from pyrochlore to a defect-fluorite type structure. Compositions in this system were prepared via mechanical milling, followed by a two-step sintering process. Structural characterization was carried out via Rietveld refinements using neutron powder diffraction data, supported by X-ray diffraction to determine the phase and location of the pyrochlore-fluorite transformation. Unit-cell parameters were determined for the whole series using Rietveld refinements as well as the Nelson–Riley function. The neutron refinement results confirmed that the cation disorder was independent of the anion Frenkel disorder. The relation between the x -parameter in the oxygen 48 f position and anion Frenkel disorder was found to be linear for the pyrochlore structure. The ionic conductivity studies were undertaken via AC impedance analysis to determine the electronic behaviour and its relation to the structural change in the temperature range 300°C–700 °C. The trends in ionic conductivity and activation energy were explained structurally via neutron powder diffraction and X-ray diffraction data. The pyrochlore-fluorite boundary composition (at y = 0.5) exhibited the lowest activation energy and highest ionic conductivity. [ABSTRACT FROM AUTHOR]

In this work a series of stoichiometric Cu 2 ZnSnS 4 (CZTS) samples annealed at different temperatures in the range of 473–623 K were investigated. The temperature dependence of the Cu/Zn-order-disorder behavior was analyzed by neutron powder diffraction measurements. Cu fully occupies the 2a and Sn the 2b position within the whole temperature range. For Zn and the remaining Cu on sites 2d and 2c, a clear change from ordered to disordered kesterite structure is found. The critical temperature T c for this Landau-type second order transition was determined as 552±2 K. It was found that in Cu 2 ZnSnS 4 very long annealing times are necessary to reach equilibrium at low temperatures. [ABSTRACT FROM AUTHOR]

Structural order emerging in the liquid state necessitates a critical degree of anisotropy of the molecules. For example, liquid crystals and Langmuir monolayers require rod- or disc-shaped and long-chain amphiphilic molecules, respectively, to break the isotropic symmetry of liquids. In this Letter we present results from molecular dynamics simulations demonstrating that in two-dimensional liquids, a significantly smaller degree of anisotropy is sufficient to allow structural organization. In fact, the condensed phase of the smallest amphiphilic molecule, methanol, confined between two, or adsorbed on, graphene sheets forms a monolayer characterized by long chains of molecules. Intrachain interactions are dominated by hydrogen bonds, whereas interchain interactions are dispersive. Upon a decrease in density toward a gaslike state, these strings are transformed into rings. The two-dimensional liquid phase of methanol undergoes another transition upon cooling; in this case, the order-disorder transition is characterized by a low-temperature phase in which the hydrogen bond dipoles of neighboring strings adopt an antiparallel orientation. [ABSTRACT FROM AUTHOR]

We investigated the chemical ordering in PtNi nanocrystals fabricated on sapphire substrate using in-situ synchrotron X-ray scattering. Nanocrystals with composition close to 1:1 were ordered in the tetragonal L1 0 structure at low temperatures. The transition to disordered FCC structure occurred at around 640 °C and substantial hysteresis of about 50 K was observed. Nanocrystals of smaller sizes fabricated under the same conditions were Ni rich and ordered into Cu 3 Au type L1 2 structure. Significantly higher degree of chemical ordering was observed in L1 2 structure than in L1 0 structure. [ABSTRACT FROM AUTHOR]

The effect of plastic deformation on the structure and properties of the ordered Cu–56Au (at.%) alloy has been studied. The deformation strain has been expressed in the cross-section area reduction (CSAR) percent from 10 to 80%. The dependences of electrical resistivity and microhardness on CSAR of both ordered and disordered alloy specimens have been plotted. Mechanical tensile tests of specimens in various structural states have also been carried out. It has been shown that after plastic deformation, the microhardness of the pre-ordered Cu–56Au alloy increases significantly and becomes higher than the microhardness of the severely deformed initially disordered alloy. It has been established that the deformation up to 70% CSAR does not cause a complete destruction of the atomic order. It has been shown that moderate plastic deformation (at 10–30% CSAR) of the ordered Cu–56Au alloy leads to obtaining of a thermal stability material exhibiting an excellent balance between high strength and low electrical resistivity. Such behavior of the alloy is attributed to the occurrence of an enriched dislocation density in the deformed ordered structure in which the deformation-induced disordered phase has not begun to form yet. • Influence of the plastic deformation on the structure and properties of the ordered Cu–56Au alloy have been investigated. • Moderate deformation of the ordered Cu–56Au alloy leads to the formation of a high-strength and thermally stable material. • At the initial stage ofthe deformation, only the increase of dislocation density occurs in the ordered Cu–56Au alloy. • Traces of the deformation-induced formation of the disordered phase have been found after deformation strain at 30%. • Moderate plastic deformation of ordered alloys can be considered as a new way to obtain promisimg functional materials. [ABSTRACT FROM AUTHOR]

The conductivity plots of the disc-shaped pallet samples are almost linear, consistent with the Arrhenius equation, and an increase in total dopant concentration leads to a decrease in conductivity. [Display omitted] • High–temperature conductivity tests (>700 °C) can have an impact on the cubic δ–phase stability. • To achieve highest conductivity, the dopant concentration should be kept as low as possible. • The order–disorder transition was observed in the samples 5Tb10Gd5Sm and 5Tb5Gd15Sm. • The highest conductivity was found to be 0.07 S/cm at 750 °C with a dopant content ratio of 2:1:1. In this study, the effects of a triple doping strategy on the microstructure and electrical conductivity of Tb–Gd–Sm co–doped Bi 2 O 3 systems were investigated. The XRD patterns generated after the conductivity measurements confirm that high–temperature conductivity tests (>700 °C) can help to stabilize the cubic δ–phase by creating a secondary annealing effect. At about 730 °C, the phase transition (α → δ) is noticeable on both the DTA curve and the conductivity plot of the sample 5Tb5Gd5Sm. The order–disorder transition is recognizable in samples 5Tb10Gd5Sm and 5Tb5Gd15Sm, resulting in two distinct conductivity regions. At 750 °C, the sample 10Tb5Gd5Sm has the highest conductivity of 0.0758 S/cm as well as the lowest activation energy of 0.27 eV. [ABSTRACT FROM AUTHOR]

In the statistical theory of the ordering of carbon atoms in the z sublattice of martensite, the most important role is played by the parameter of the strain interaction of carbon atoms λ, which determines the critical temperature of the bcc-bct transition. The values of this parameter (6-11 eV/atom) obtained in recent years by the methods of computer simulation differ significantly from the value λ = 2.73 eV/atom obtained by A. G. Khachaturyan. In this article, we calculated the value of λ by two methods based on the molecular-dynamics simulation of the ordering of carbon atoms in the lattice of martensite at temperatures of 500, 750, 900, and 1000 K in a wide range of carbon concentrations, which includes c. No tails of ordering below c have been revealed. It has been shown analytically that there is an inaccuracy in the Khachaturyan theory of ordering for the crystal in an elastic environment. After eliminating this inaccuracy, no tails of the order parameter appear; the tetragonality changes jumpwise from η = 0 to η = 0.75 at c = 2.9 kT/λ instead of η = 0.5 and c= 2.77 kT/λ for an isolated crystal. Upon the simulation, clustering of carbon atoms was revealed in the form of platelike pileups along {102} planes separated by flat regions where no carbon atoms were present. The influence of short-range order in the arrangement of neighboring carbon atoms on the thermodynamics of ordering is discussed. [ABSTRACT FROM AUTHOR]

Terahertz transmission spectra of nonadecane (C 19 H 40 ) in the crystalline and rotator phases were measured over the frequency range of 1–5.5 THz. The absorption peak at 2.2 THz, related to intermolecular interaction, was observed only in the crystalline phase. Using the absorbance at this frequency, the transition between the two phases was investigated. A model of the orientational order–disorder transition of the molecule is presented to qualitatively explain the transition rate. [ABSTRACT FROM AUTHOR]

We report the physical characteristics of InGaZnO 4 films deposited at various temperatures. The films were deposited on Al 2 O 3 (0001) substrates using pulsed laser deposition technique. Based on X-ray diffraction and field emission scanning electron microscopy measurements, the crystal structure changed from amorphous to polycrystalline as deposition temperature increased to 550 °C. Furthermore, UV–vis measurements revealed a decrease in tail state i.e. improvement of local ordering, resulting in an increase of optical band-gap energy as deposition temperature increased. The core-level X-ray photoelectron spectra also showed an increase (decrease) in metal-oxide (oxygen deficiency) bond as the deposition temperature increased. The carrier concentration, Hall mobility and conductivity variation with deposition temperature are related to the competition between oxygen deficiency and grain boundary formation. [ABSTRACT FROM AUTHOR]

Phase equilibria at 800, 900 and 1000 °C, as well as order–disorder and magnetic transitions of Heusler-type ordered phase were investigated in the Co–Mn–Ga ternary system. The β phase with bcc structure including the Heusler-type ordered phase exists in a wide composition range of the ternary system. It was confirmed by STEM–HAADF observation that the crystal structure of the Heusler-type ordered alloy Mn 2 CoGa is L 2 1b -type Fm 3 ¯ m (i.e., (Mn,Co) 2 MnGa), but not inverse-Heusler (Hg 2 CuTi) type F 4 ¯ 3 m . The L 2 1 / B 2 order–disorder transition temperature shows a maximum at the stoichiometric composition of Co 2 MnGa and the Curie temperature of the L 2 1 phase decreases with increasing Ga content. Magnetic moments converted from magnetization curves at 4.2 K for Co x Mn (76− x ) Ga 24 alloys well follow the generalized Slater–Pauling rule in the composition of 25 ⩽ x ⩽ 50, and magnetization curves indicate very small high-field magnetic susceptibility. [ABSTRACT FROM AUTHOR]