(2020). In memory of Ihor Stasyuk. Phase Transitions. Ahead of Print.

ABSTRACT Studies on critical behaviour associated with different phase transitions are of fundamental importance in condensed matter physics and may suitably be explored in the realm of soft materials. In this work, we report on high-resolution measurements of specific heat capacity (C p) from modulated differential scanning calorimetry (MDSC) to investigate the critical behaviour at the smectic A

ABSTRACT The effect of the one defects on borophene tri-Layer structure consisting of nineteen hexagonal B36 units of a mixed spin S(A) = 7/2, S(B) = 2 and S(C) = 1/2 was study via Monte Carlo simulation in the absence and presence of external magnetic and crystal fields. Monte Carlo simulation method with the Metropolis algorithm is used to study magnetic properties of this system. To complete this

ABSTRACT Neutron diffraction studies were performed on xSrO-(100-x)TeO2 (x = 5, 7.5 and 10 mol%) glass, anti-glass and crystalline samples. For the structural modeling, Fourier transformation, Reverse Monte Carlo (RMC) simulations and Rietveld refinement were used. The pair distribution functions show the nearest neighbor peaks of Sr—O, Te—O and O—O correlations at 2.64, 1.95 and 2.70 Å, respectively

ABSTRACT In this work, a novel nanocomposite was prepared by filling cellulose nanopores with a classical ferroelectric of polycrystalline ammonium sulfate for clarifying its anomalous properties under nanoconfinement conditions and the influence of dielectric matrix. The filler content was estimated as 61 wt%. The experiments were conducted under a weak external electric field (1 V/cm) in the frequency

We report the synthesis of barium cerium manganite (BaMn0.94Ce0.06O3) single perovskite by using a conventional high-temperature solid-state reaction method. A structural phase transition occurs from hexagonal to orthorhombic confirmed by XRD data analysis after doping cerium (Ce) to the pure barium manganite (BaMnO3) matrix. The average crystallite size of the sample is about 63.38 nm. The lattice

We present a theoretical study on electronic structure and chemical trends of zinc-blende GaP under compression up to 100 kbar obtained from a pseudopotential approach calculations. The influence of high pressure on the features of interest has been examined and reported. The dynamics of chemical bonds in the compound in question is investigated by analyzing the profiles of the electron charge densities

Density functional theory (DFT) based full-potential linearized augmented plane wave (FP-LAPW) method approach has been used to investigate the phase stability, pressure-induced phase transition and electronic properties of AlP, AlAs and AlSb compounds. The study has been performed for the zinc blende (B3), rocksalt (B1), wurtzite (B4), NiAs (B8) and CsCl (B2) phases. For structural properties, the

AgI can transform a face-centred cubic lattice structure under pressures in the range 0.4–11.3 GPa. These phases also exhibit high ionic conductivities, particularly at high temperatures. The full-potential linear muffin-tin-orbital (FP-LMTO) method is used to investigate the ion conduction mechanisms of AgI under high pressures, wherein the exchange correlation energies of electrons are calculated

In this manuscript, we discussed an ab initio analysis of the structural, electronic, optical and magnetic properties of LnO (Ln = Eu, Dy) compounds. Our assessments were performed by the augmented plane wave method FP LAPW founded on the DFT (density functional theory) and introduced in the Wien2k calculation code. This investigation of the electronic band, structural, optical and magnetic properties

The Fe-substituted Na0.5Bi0.5TiO3 (NBT) ceramics were prepared through solid-state reaction technique. X-ray diffraction analysis indicated the formation of perovskite structure with rhombohedral symmetry. It was found that 0.5 mol% Fe and 0.1 mol% Fe dopant concentration increases the depolarization temperature Td , Tm, the dielectric loss and electric conductivity. The effects can be mainly the result

The IrxRe1−x (0.1≤ x ≤0.7) alloys are hexagonal structured inclusion material used in an on-orbit communication satellite. The characteristic features of high-temperature alloys IrxRe1−x (0.1≤ x ≤0.7) are investigated by the theoretical evaluation of thermophysical and ultrasonic properties at room temperature. Initially, higher-order elastic constants of the alloys are calculated using the simple

We study a complex mixture with bidispersity in size and polydispersity in energy using computer simulation. The energy polydispersity between the bidisperse particles is introduced by considering random pair-wise interactions. Extensive molecular dynamics simulations are performed to compute potential energy and neighborhood identity ordering (NIO) parameter as a function of temperature for different

Dielectric spectroscopic measurements have been reported on three synthesized pure liquid crystalline compounds having paraelectric (SmA*), ferroelectric (SmC*) and antiferroelectric (SmCA*) phases in the frequency range of 40 Hz–25 MHz. Several relaxation modes i.e. low-frequency PL Mode and high-frequency PH Mode in the SmCA* phase, Goldstone Mode (GM) in SmC* phase and Soft Mode (SM) in SmA* phase

Semi-crystalline polymers are observed to change their mechanical properties upon processing due to the changes in the crystallinity of the polymer. This paper investigates the changes in the crystallinity and mechanical properties of biaxially stretched polyethylene terephthalate, PET, for different stretch ratios (or strains). Each stretched PET sample was heated to 100°C in a biaxial stretching

Basing on dilatometric and optical anisotropy studies, we have obtained (x, T)-phase diagram for TlIn(S1–xSex)2 solid solutions in the range 0 ≤ × ≤ 0.25 of selenium concentrations. It has been found that increasing selenium concentration leads to decrease in almost all of phase transition (PT) temperatures. At the same time, the temperature Ti of PT into incommensurate phase for the polytype c = c

First-principles calculations of density functional theory (DFT) using the generalized gradient approximation (GGA) and generalized gradient approximation with the Hubbard U (GGA + U) for the exchange-correlation energy functional are used to investigate the structural, electronic, and magnetic properties of the spinel system C d x N i 1 − x F e 2 O 4 in the range 0 ≤ x ≤ 1 . High-temperature series

The IrxRe1−x (0.1≤ x ≤0.7) alloys are hexagonal structured inclusion material used in an on-orbit communication satellite. The characteristic features of high-temperature alloys IrxRe1−x (0.1≤ x ≤0.7) are investigated by the theoretical evaluation of thermophysical and ultrasonic properties at room temperature. Initially, higher-order elastic constants of the alloys are calculated using the simple

Dielectric spectroscopic measurements have been reported on three synthesized pure liquid crystalline compounds having paraelectric (SmA*), ferroelectric (SmC*) and antiferroelectric (SmCA*) phases in the frequency range of 40 Hz–25 MHz. Several relaxation modes i.e. low-frequency PL Mode and high-frequency PH Mode in the SmCA* phase, Goldstone Mode (GM) in SmC* phase and Soft Mode (SM) in SmA* phase

Basing on dilatometric and optical anisotropy studies, we have obtained (x, T)-phase diagram for TlIn(S1–xSex)2 solid solutions in the range 0 ≤ × ≤ 0.25 of selenium concentrations. It has been found that increasing selenium concentration leads to decrease in almost all of phase transition (PT) temperatures. At the same time, the temperature Ti of PT into incommensurate phase for the polytype c = c

Semi-crystalline polymers are observed to change their mechanical properties upon processing due to the changes in the crystallinity of the polymer. This paper investigates the changes in the crystallinity and mechanical properties of biaxially stretched polyethylene terephthalate, PET, for different stretch ratios (or strains). Each stretched PET sample was heated to 100°C in a biaxial stretching

We study a complex mixture with bidispersity in size and polydispersity in energy using computer simulation. The energy polydispersity between the bidisperse particles is introduced by considering random pair-wise interactions. Extensive molecular dynamics simulations are performed to compute potential energy and neighborhood identity ordering (NIO) parameter as a function of temperature for different

La0.7Ga0.3Fel-xTixO3 (x = 0, 0.1, 0.2, and 0.3) polycrystalline compounds were successfully prepared using the solid–solid process. The structural study proves that the samples are centrosymmetric at room temperature. From admittance spectroscopy, it is shown that the frequency dependence of conductivity is correctly fitted by the empirical Jonscher's law, implying a semiconductor behavior. The microstructure

Novel symmetrical carbazole-thieno[3,4-c]pyrrole-4,6-dione-carbazoles (Carbazole-TPD-Carbazole) were designed and synthesised as donor–acceptor-donor (D-A-D) materials. The correlations between their molecular structures, differing only in the length of the symmetrical terminal linear alkyl chains attached to a carbazole-TPD-carbazole moiety in the molecular core, and their mesomorphic behaviour, transition

The Full-Potential Linearized-Augmented Plane Wave with Local Orbitals method (FPLAPW + LO) and the generalised gradient approximation (GGA) exchange–correlation potential are used to study the structural, electronic, elastic and mechanical properties of five different structures of ScX [X = S, Se]. The electronic properties are calculated using the modified Becke–Johnson (mBJ) approach. The elastic

In this study, the dielectric properties and ac conductivity mechanism of pyridine-based rod-like liquid crystals (LC1 and LC2), which show enantiotropic smectic A mesophase, have been investigated by impedance spectroscopy within the frequency interval of 1 kHz–2 MHz. The variation of real and imaginary component of dielectric constant with angular frequency has been investigated. The temperature-dependent

Pure and Sb-doped Cu2Se thin films have been prepared by the simple chemical bath deposition method. The structural, morphological, compositional, optical and electrical properties of the Cu2Se films were analysed using x-ray diffraction (XRD), scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDAX), UV-Visible (UV–Vis) spectrophotometry and Hall Effect set-up, respectively

BaZrO2.9 compound was prepared by the sol–gel process. Electrical and dielectric characterizations of the materials were performed using complex impedance spectroscopy technique over a frequency range of 100 Hz to 1 MHz and in a temperature range from 305 K to 370 K. ac conductivity and dielectric properties have been studied in order to explore the relaxation mechanisms in this compound. It can be

The multitude of effected works about oxides obtained from the system Cu/Al2O3 proves the increasing interest for these oxides in synthesis and technological applications, due to their physical and chemical properties. In this work, CuAlO2 and spinel CuAl2O4 were prepared by conventional technique of brazing in oxidizing atmosphere starting from the Cu/Al2O3 assembly. Thermal treatment was performed

The phase diagrams and magnetizations of Ising nanoparticles with high critical temperature, consisting of atoms with a negative exchange interaction between the surface and the core, are investigated by using the effective-field theory with correlations. They show a compensation point below their critical temperatures, although they have not ferrimagnetic spin configuration. The effects of an applied

We perform a simulation of the structural transition and structural heterogeneity (SH) in silica glass at 500 K, in the range 0–100 GPa. Topological analysis is performed based on the basic units and transition of Oxx and Oxy atoms (x, y = 4, 5, 6). The result indicates that the structure of silica glass comprises D4, D5 or D6 domain, depending on pressure. In the range 5–20 GPa, silica glass occurs

The ground-state properties of ZnO compound in the Wurtzite-type structure are investigated using the optimization of total-energy calculations based on the full-potential augmented plane-wave (FP-LAPW) method within the density functional theory (DFT). The exchange–correlation potential for structural properties is calculated by the generalized gradient approximation (GGA), while for electronic properties

Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 (BZT-xBCT) is a promising lead-free ferroelectric system with high piezoelectricity. Here we carry out phenomenological calculations to explore phase stability and electric field induced phase transition. Study of free energy variation near phase boundaries revealed ultralow energy barrier in single orthorhombic phase region and phase coexistence around inter-ferroelectric

PLZT ceramics containing 9 mol% La and 50–70 mol% Zr were prepared by two-stage sintering to enhance the densification and the microstructure. Dielectric properties were investigated and the phase transition from relaxor to normal ferroelectric as an increasing amount of Zr could be observed. Induced strain (butterfly loop) and polarization (hysteresis loop) were measured at the maximum electric field

The structural, electronic, mechanical and magnetic properties of Fe2-x Co x TiSn (x = 0, 0.5, 1, 1.5, 2) Heusler alloys in L21 (Cu2MnAl prototype) and XA (Hg2CuTi) phases are analysed. The structural optimization confirms the stability of these alloys in L21 phase. As the pressure is increased, the structural phase transition from L21 to XA phase is predicted at the pressures of 123.34, 74.27, 47

A non-lead electronic sample with chemical composition Bi(Ni2/3V1/3)O3 (BNV) has been fabricated via a conventional ceramic technology. The resistive, capacitive and conducting properties of the specimen are examined experimentally. The formation of the sample with orthorhombic crystal system is ensured through X-Ray diffraction spectrum. Detailed analysis of the temperature-frequency dependent dielectric

In this article, the isoconversional crystallization behavior of TiO2 nanoparticles prepared using titanium glycolate and titanium malate water-soluble precursors at alkaline and acidic conditions was investigated. Thermal decomposition experiments were carried out using thermo gravimetric (TG) analysis and the phase structure was determined by powdered X-ray diffraction (PXRD) analysis. The phase

Effect of film thickness on the magnetic properties of inverse spinel ( F e 3 + ) [ F e 3 + F e 2 + ] O 4 2 − has been studied using Monte Carlo simulation. The critical temperature has been obtained for different film thickness up to L = 13. The free boundary conditions along L direction have been used. The magnetic hysteresis is obtained for different temperatures and for different film thickness

In this article, the isoconversional crystallization behavior of TiO2 nanoparticles prepared using titanium glycolate and titanium malate water-soluble precursors at alkaline and acidic conditions was investigated. Thermal decomposition experiments were carried out using thermo gravimetric (TG) analysis and the phase structure was determined by powdered X-ray diffraction (PXRD) analysis. The phase

The ground-state properties of ZnO compound in the Wurtzite-type structure are investigated using the optimization of total-energy calculations based on the full-potential augmented plane-wave (FP-LAPW) method within the density functional theory (DFT). The exchange–correlation potential for structural properties is calculated by the generalized gradient approximation (GGA), while for electronic properties

We consider the interacting helical liquid system at the one-dimensional edge of a two-dimensional topological insulator, coupled to an external magnetic field and s-wave superconductor and map it to an XYZ spin chain system. This model undergoes quantum Berezinskii–Kosterlitz–Thouless (BKT) transition with two limiting conditions. We derive the renormalization group (RG) equations explicitly and also

The real-space total scattering atomic Pair Distribution Function (PDF) method has been used to study the effect of temperature (T) on the structural features of the manganite Nd0.5 Sr0.5MnO3. The powder X-ray diffraction data were collected as a function of T ranging from 92 to 300 K. The PDF data were analyzed at a Qmax value of 28Å−1 and a room temperature model was used for the refinement of the

The present study briefs the structural and optical properties of Gd doped BaZr0.05Ti0.95O3 ceramic synthesized via solid-state reaction (SSR) technique. The X-Ray diffraction (XRD) study reveals the formation of single phase of Gd modified BaZr0.05Ti0.95O3 ceramic. The Fourier transform infrared (FTIR) spectra are also presented in support of structural properties. The optical band-gap obtained from

A self-consistent field model for a mixture of Bose and Fermi particles is formulated. There is explored in detail the case of a delta-like interaction, for which the thermodynamic functions are obtained, and Bose–Einstein condensation of interacting particles in the presence of the admixture of fermions is studied. It is shown that at a fixed total density, the admixture of Fermi particles leads to

In this work, we have investigated the crystalline structure, martensitic transformation (MT) and magnetic properties of Co50V25-xNixGa25 (x = 5, 6, 7, 8, 9, 12.5) together with Co50V17Ni7Ga26 Heusler alloys. It was found that the MT behavior can occur in the Ni-doped Co50V25Ga25 Heusler alloys, and the MT temperature increases with the increase of Ni doping, which can reach about room temperature

Alumina nanoparticles were synthesized by thermal dehydration of Al(OH)3 (gibbsite), which shows the sequential formation of AlOOH (bohemite), γ, δ, θ, and α-alumina phases upon heat treatment in the temperature range: 150–1150°C. Alumina nanoparticles were characterized by X-ray diffraction and 27Al MAS-NMR studies to investigate the structural transitions, in particular, the changes in Al—O speciation

Interactions of rare earth elements with Ti–Si system at high temperatures are of academic interests for the development of refractory lightweight structural materials. As part of the fundamental research of multicomponent Ti–Si-based alloys, solid phase equilibria of the Gd–Ti–Si ternary system at 1073 K and Er–Ti–Si ternary system at 1273 K were investigated through analysis of X-ray diffraction

The paper is devoted to the molecular dynamics calculations of the liquidus curve for the LiCl-KCl binary mixture. The two-phase simulations of the initial cell in an NPT ensemble were performed. Pairwise interactions are derived from the second-order Møller-Plesset perturbation theory and are well described by the Born–Mayer potential. The liquid–solid equilibria were observed upon heating of two

The double perovskite ceramic Pb1.5Mg0.5BiNbO6 is synthesized by the simplest and cheapest technique popularly known as mixed oxide route at medium temperature. The effect of ‘Mg’ doping at the A site of Pb2BiNbO6 on the crystal structure is shown from the room temperature X-ray diffraction pattern. The SEM picture of the sintered sample pellet exhibits the uniform distributions of small grains with

A series of composite “BST”+ “NCZMF” were prepared using high energy ball milling method. The structural characterization for synthesized samples were carried out using (XRD), (FTIR) and (HRTEM). The surface morphology of BST at different ferrite content (x%) was studied by (SEM). XRD pattern confirms that both parent phases BST and spinel NCZMF are pure phases. The sample x = 40% has the highest value

In this paper, the magnetic properties of a bi-layer nano-stanene like structure with RKKY (Ruderman-Kittel-Kasuya-Yoshida) interactions have been studied using Monte Carlo simulations. The considered system is composed of two magnetic planes with mixed spins σ = 7/2 and S = 1, separated by the non-magnetic planes (L). Firstly, the ground state phase diagrams for zero temperature are reported and discussed

In order to find a low temperature phase change material with a temperature range of 2–8°C, decyl alcohol (DA) and myristyl alcohol (MA) binary eutectic mixture was prepared based on theoretical calculation, with a mass ratio of DA: MA=87:13. DA-CA/EG with an optimal mass ratio of DA-MA: EG=14:1 was obtained after vacuum adsorption. Scanning electron microscope and Fourier transformation infrared spectroscopy

In this study, the exchange bias effect (EBE) revealed by the HCP-FCC structural phase transformation in Cobalt nanoparticles (CoNPs) are modeled and investigated by using the Ising model within the framework of the Effective Field Theory developed by Kaneyoshi. CoNPs are mixed (indistinguishable HCP and FCC) phase at T < 0.36 and T > TcFCC. For the non-structural transformation, CoNPs exhibit no exchange

The impendence spectroscopy properties of polycrystalline Nd0.67Pb0.33Mn0.9Al0.1O3 perovskites prepared by sol–gel method at two different sintering temperatures (900°C and 1100°C), have been investigated by performing the measurements as a function of temperature and frequency of electrical conductance and impedance. In the whole explored temperature range, conductance measurements show that both

The thin film growth behavior and mechanism of ZnO grown by atomic layer deposition (ALD) on Si (100) substrate was using diethylzinc (DEZn) and H2O as the zinc and oxygen sources, resperctively. The preferred orientation of ZnO on the Si (100) substrate was changed from (002) to (100). We suggest a hypothesis on the mechanism of preferred orientation change during ZnO deposition. This phenomenon seemed

Cu2+ ion-doped ZnO nanoparticles were elaborated using a low cost-effective polyol method. The structural and morphological analysis of the samples was investigated using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The dielectric and electrical properties have highlighted the dependence of frequency and temperatures on dielectric parameters using impedance spectroscopy. The

The magnetic properties (phase diagram, the thermal variations of magnetization and the reduced magnetization curve) in graphene-like Ising nanoparticles are examined by the effective-field theory with correlations. The effects of surface exchange interaction JS on the magnetic properties are discussed. When JS is larger than the critical value JSC, a nanoparticle with high critical temperature is

Appling the framework of dynamic mean-field theory based on the Glauber-type stochastic dynamics, we study the dynamic magnetic hysteresis loop (DMHL) properties of the hexagonal nanowire system with spin-2 Ising particles. We investigate the DMHL behaviors for various values of reduced temperatures and interaction parameters. We also examine the reduced temperature and interaction parameters dependences

Non-centrosymmetric to centrosymmetric structural transformation of BaZrxTi1−xO3 (x = 0, 0.05, 0.1, 0.3) as prepared by soilid state reaction was investigated from X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), pair distribution function (PDF) and Raman spectra. Tetragonal BaTiO3 transformed to orthorhombic phase for lower Zr concentration (x = 0.05) and changed to tetragonal to cubic

A higher-order Landau–Ginzburg–Devonshire theory is proposed to describe phenomenologically the complex phase transitions in the MPB region of the relaxor ferroelectric (1−x)Pb(Mg1/3Nb2/3)O3-xPbTiO3(PMN-PT) single crystals. Using the singularity theory, a structurally stable 10th-order potential with four varying expansion coefficients (a1, a11, a2 and a12) depending on temperature and composition