Properties Of Crystals Research Articles

Diffracted X-ray blinking reveals signature crystal polymorph dynamics in 1,2,3,5-Tetrabromobenzene

In this work we report findings on the study of 1,2,4,5-tetrabromobenzene (TBB) polymorphs by diffracted X-ray blinking (DXB). Using DXB it was found that on the ms-s time scale subtle fluctuations in the d-spacing between lattice planes occurs more rapidly in the γ-phase polymorph than in the β-phase, successfully identifying another distinct characterization between them. It was also found that the rate of molecular motion spiked near the phase transition temperature beyond the typical characteristic regions. This offers additional insight on previous reports of anisotropic lattice softening and strain accumulation near the phase transition temperature that are key to the mechanically responsive properties of TBB crystals. The present study on ms-s crystalline dynamics by DXB for mechanically responsive organic crystals also serves as a guideline for future study of more complicated mechanically responsive crystal behaviors.

Crystallization, thermal, and mechanical properties of ethylene-propylene block copolymer/random copolymer blends

Crystallization, thermal, and mechanical properties of ethylene-propylene block copolymer/random copolymer blends

Thermally Triggered Transient Photodetector Based on Iodine Single Crystal

AbstractTransient electronic devices are electronic systems that can self‐destruct and disappear under external stimuli after completing a specific function. The basic triggering principle of most transient electronic devices so far has been limited to biodegradation or solution‐degradation of the active materials, or destruction of specific substrates. Here, a photodetector based on iodine single crystal grown by the anti‐solvent vapor‐assisted crystallization method is designed and fabricated, showing a responsivity of 4.45 × 10−3 mA W−1 at a bias of 5 V, with a broadband response ranging from 405 to 808 nm. By integrating the photodetector with a heating module, an innovative transient electronic device is constructed by exploiting the sublimation property of iodine crystal. This device operates stably at room temperature and can be fully degraded within 450 s of heating, effectively achieving self‐destruction. This work presents a novel approach for the growth of iodine single crystal, which demonstrates the practical application in the development of transient photodetectors with controllable and rapid response, providing valuable insights into the design of future transient devices.

Chemical Disorder-Driven Cluster Spin Glass in Pseudobinary Co2Zn10.2Mn0.8: An Experimental and Theoretical Study.

The investigation focuses on Mn substitution in Co2Zn11, prepared by pursuing a solid-state sealed tube method under high vacuum. We report the crystal structure and magnetic properties of Co2Zn10.2Mn0.8 in detail. Co2Zn10.2Mn0.8 adopts the noncentrosymmetric space group I4̅3m (No. 217), and the distribution of Co, Mn, and Zn atoms is confirmed using X-ray and neutron powder diffraction (NPD) techniques. The magnetic studies reveal cluster glass (CG) formation below the spin-freezing temperature of 23.1 K in Co2Zn10.2Mn0.8, also indicated by the large value of the characteristic relaxation time (τ0) of ∼10-8 s. This large value of τ0 supports the formation of magnetic clusters. The magnetic moment primarily originates due to the spins of Mn atoms, which is realized from significant differences between majority- and minority-spin channels of Mn 3d states in the projected density of states curves.

Effects of Multi-Fluorinated Liquid Crystals with High Refractive Index on the Electro-Optical Properties of Polymer-Dispersed Liquid Crystals

Effects of Multi-Fluorinated Liquid Crystals with High Refractive Index on the Electro-Optical Properties of Polymer-Dispersed Liquid Crystals

Crystal structure, magnetic properties, and tunable Kondo effect in a new compound Nd5ScSb12

Crystal structure, magnetic properties, and tunable Kondo effect in a new compound Nd₅ScSb₁₂

Backscattering properties of quasi-horizontally oriented ice crystals for scanning lidars with small tilt angles

Quasi-horizontal orientations of ice crystals were conventionally described using a Gaussian distribution. However, recent research has shown that the exponential distribution provides a more accurate representation of them. The backscattering properties of plate-like and column-like ice crystals with the exponential distribution for lidar with tilt angles ranging from 0° to 15° off-zenith are investigated for the first time in this study. It reveals that using the realistic distribution law significantly impacts the scanning lidar’s retrieval algorithms, especially in the case of plate-like ice crystals. It is found that the color ratio is also sensitive to the plate’s flutter, while the linear depolarization ratio is sensitive to the orientation of the columns. These new results are very crucial for adjusting the micro-pulse lidar network (MPLNET) retrieval algorithms.

What Is More Important When Calculating the Thermodynamic Properties of Organic Crystals, Density Functional, Supercell, or Energy Second-Order Derivative Method Choice?

What Is More Important When Calculating the Thermodynamic Properties of Organic Crystals, Density Functional, Supercell, or Energy Second-Order Derivative Method Choice?

Tuning the Properties of Dodecylpyridinium Metallosurfactants: The Role of Iron-Based Counterions.

Metallosurfactants combine the unique soft-matter properties of surfactants with magnetic functionalities of metal ions. The inclusion of iron-based species, in particular, can further boost the functionality of the material, owing to iron's ability to adopt multiple oxidation states and form both high-spin and low-spin complexes. Motivated by this, a series of hybrid inorganic-organic dodecylpyridinium metallosurfactants with iron-containing counterions was developed. It was established that using either divalent or trivalent iron halides in a straightforward synthetic procedure yields C12Py-metallosurfactants with distinct complex counterions: (C12Py)2[Fe2X6O] and (C12Py)[FeX4] (X = Cl or Br), respectively. A combination of techniques-including conductometry, dynamic and electrophoretic light scattering, single-crystal and thermogravimetric analysis, and magnetic measurements-provided in-depth insights into their solution and solid-state properties. The presence of different iron-based counterions significantly influences the crystal structure (interdigitated vs. non-interdigitated bilayers), magnetic properties (paramagnetic vs. nonmagnetic singlet ground state), and self-assembly (vesicles vs. micelles) of the dodecylpyridinium series. To our knowledge, this is the first report on the synthesis and characterization of hybrid organic-inorganic metallosurfactants containing the μ-oxo-hexahalo-diferrate anion.

Effect of Confinement on the Structural, Dielectric, and Dynamic Properties of Liquid Crystals in Anopores

Based on data from broadband dielectric spectroscopy (BDS) and a molecular model based on the Landau–de Gennes concept, the effect of confinement on the structural, dielectric, and dynamic properties of 4-n-pentyl-4′-cyanobiphenyl (5CB) in the nematic phase is studied. The dielectric permittivity and relaxation times were previously obtained by the BDS technique in a wide frequency range (1MHz≤f≤1GHz) in the nematic phase composed of 5CB molecules confined to Anopore membranes with pore sizes of 0.2 μm. The distance-dependent values of the order parameter P2(r), the relaxation time τ(r)≡τ001(r), the rotational diffusion coefficient D⊥(r), and both rotational viscosity coefficients γi(r) (i=1,2) as functions of the distance r away from the bounding surface are calculated by a combination of existing statistical-mechanical approaches and data obtained by the BDS technique. Reasonable agreement between the calculated and experimental values of γi(i=1,2) for bulk 5CB is obtained.

Long-wave infrared upconversion detection based on a ZnGeP2 crystal.

Longwave infrared (LWIR) detection is achieved through nonlinear upconversion with a ZnGeP2 crystal. The target LWIR light interacts efficiently with a 1.06 μm probe laser, converting into a near-infrared signal. This detection configuration offers the following advantages: a broad response wavelength band of 9.69-12.38 μm and a high optical-to-optical responsivity of 150-200%, attributed to the enhanced properties of a custom-fabricated ZnGeP2 crystal. Theoretical interpretations of these experimental outcomes are based on coupled-wave equations. At room temperature, the system achieves a minimal detectable energy in the sub-fJ (ns pulses) range. It has the potential for wide-field imaging when designed as noncritical phase matching, owing to its large acceptance angle.

Study of Structure and Optical Properties of TiO2 Doped with Metal

TiO2 dopped with CuO nanocomposites are one of the most capable materials for cost-effective, reliable, and solar energy saving in addition to the development of substitute commercial in solar production and energy storage while increasing their efficiency in desired applications. This present research aims to investigate the effect of the addition on the optical and structural properties of the TiO2 using the Sol-gel method at different (CuO) concentrations ranging between 5% and 15%. The crystal structure and optical properties of synthesized samples were examined using X-Ray Diffraction (XRD), and Ultraviolet–Visible spectroscopy (UV) respectively. All samples showed Anatase crystal structure with an observed increase in the crystal size as the CuO concertation increased from 100.9 nm to 207.3 nm. In addition, this increase in percentages has affected the optical parameters by enhancing the optical proficiency for the prepared samples with a noticed slight shift to the visible region to improve its efficiency to be used as photocatalytic and energy-saving applications in more reliable and effective methods. This study has yielded significant insights that may aid in the advancement of optoelectronic applications in industries by reducing costs. These results could be instrumental in enhancing production processes and making the use of more viable and cost-effective options for industrial operations.

Crystal Structure and Physical Properties of Au4Al-Type Suboxides in the Ti-Rh-Si-O and Ti-Ir-Si-O Systems.

This study reports the successful synthesis and comprehensive characterization of Ti3RhSiO and Ti3IrSiO, the earliest identified members of Ti-based Au4Al-type materials. These compounds crystallize in the cubic space group P213 (No. 198), with refined lattice parameters of 6.75362(2) Å and 6.75524(1) Å, respectively. Oxygen plays a crucial role in stabilizing the cubic phase, as confirmed by synchrotron X-ray diffraction and the absence of this phase in oxygen-free samples. First-principles calculations and resistivity measurements reveal a robust multiband metallic character, with Ti-3d and Rh-4d (or Ir-5d) orbitals contributing significantly at the Fermi level. Specific heat analysis highlights weak anharmonic lattice vibrations, while magnetoresistance measurements demonstrate negligible field sensitivity. These unique structural and electronic properties provide valuable insights into the development of Ti-based Au4Al-type compounds, opening new avenues for fundamental materials research.

Deep Learning Analysis of Localized Interlayer Stacking Displacement and Dynamics in Bilayer Phosphorene.

The interlayer displacement has recently emerged as a crucial tuning parameter to control diverse physical properties in layered crystals. Transmission electron microscopy (TEM), an exceptionally powerful tool for structural analysis, directly observes the interlayer stacking and strain fields in various crystals. However, conventional analysis methods based on high-resolution phase-contrast TEM images are inadequate for recognizing spatially varying unit-cell patterns and their associated structure factors, hindering precise determination of interlayer displacements. Here, a deep learning-based analysis is introduced for atomic resolution TEM images, enabling unit-cell pattern recognition and precise identification of interlayer stacking displacement in bilayer phosphorene. The deep learning model applied to bilayer phosphorene accurately determines stacking displacement, with an error level of 3.3% displacement within the unit cell and a spatial resolution approaching the individual unit-cell level. Additionally, the model successfully processes a large set of in situ TEM data, capturing spatially varying, time-dependent interlayer displacement dynamics associated with edge reconstruction, demonstrating its potential for processing large-scale microscopy datasets.

Elastic properties of three-dimensional Yukawa or dust crystals from molecular dynamics simulations

This paper presents the calculation of elastic properties of three-dimensional Yukawa or dust crystals using molecular dynamics simulations. The elastic properties are computed by deforming (compressing/expanding) the dust crystals along different directions. The stress and strain of the deformed crystal are used to calculate elastic properties. The bulk modulus, shear modulus, and Poisson's ratio are determined as a function of shielding parameter κ and strong coupling parameter Γ. The bulk and shear modulus values at 0 K temperature are consistent with the previous literature results, while the finite-temperature results are new. The finite-temperature bulk modulus of Yukawa crystals is found to be higher than that of 0 K crystals. The shear modulus of the Yukawa solids decreases nonlinearly near the solid–liquid boundary in the premelting region. The Poisson's ratio of Yukawa crystals changes sharply at the solid–liquid boundary, emphasizing its potential for identifying phase transitions and assessing incompressibility in Yukawa systems. The bulk and shear moduli calculated in this paper are useful for determining accurate values of sound and shear velocity in Yukawa systems across a wide range of the (κ, Γ) parameter space.

Enhancement in mechanical, thermal, optical and di-/piezo-/ferro-electrical properties of triglycine sulphate single crystals by the dye processing

Enhancement in mechanical, thermal, optical and di-/piezo-/ferro-electrical properties of triglycine sulphate single crystals by the dye processing

Tm-concentration dependence on photoluminescence and scintillation properties of Tm-doped Gd2SrAl2O7 single crystals

Tm-concentration dependence on photoluminescence and scintillation properties of Tm-doped Gd2SrAl2O7 single crystals

Decoding the effect of defect and domain on piezoelectric properties of K0.5Na0.5NbO3-based single crystals

The ultra-high piezoelectric activity of K0.5Na0.5NbO3 (KNN)-based single crystals with excellent electromechanical coupling characteristics has attracted great interest. However, the growth of KNN-based single crystals is restricted by their high melting point and harsh equipment conditions. In this work, a large-sized single crystal of (K0.5Na0.5)0.994Bi0.006Nb0.998Cu0.004O3 (KNNBC) was grown using an inexpensive and simple seed-free solid state crystal growth method. The growth mechanism, domain structures, defects, piezoelectric properties, as well as the conduction mechanisms of the KNNBC single crystal were systematically investigated. A significant piezoelectric coefficient (d33) as high as 392 pC/N is obtained in the KNNBC single crystal, which is three times higher than that of ceramics with the same composition, and the single crystal also maintains a high Curie temperature (Tc ∼ 399 °C). The superior piezoelectric properties are believed to stem from the ordered arrangement of large-sized striped domains (∼300 nm) and the sensitivity to polarization rotation due to the flattening of the Landau energy density. Additionally, the spontaneous polarization combined with complex defect dipoles consisting of Cu2+ ions and O2− vacancies effectively modulates both the quality factor (Qm) and the piezoelectric coefficient (d33) of the single crystals. This work broadens the growth strategy of high-performance KNN-based single crystals and highlights the great benefits of the synergistic modulation of defects and domains on the piezoelectric properties of single crystals.

Thermophysical properties of single crystals and ceramics based on thallium and silver halides

Thermophysical properties of single crystals and ceramics based on thallium and silver halides

An insight into experimental and theoretical thermoelectric property of antimony and tellurium-doped Bi2Se3 single crystals

The thermoelectric properties of Bi2Se3 single crystals were investigated with Sb and Te co-doping using a modified vertical Bridgman method, complemented by theoretical studies. X-ray diffraction confirmed the rhombohedral crystal structure with an R 3¯ m space group. High-resolution X-ray diffraction (HR-XRD) analysis revealed a high degree of periodicity, threefold symmetry, and c-axis growth through θ − 2θ scans. Hall effect and Seebeck coefficient measurements indicated n-type conductivity across all samples, with a carrier concentration of approximately 1025 m−3. At 300 K, the electrical resistivity of the (Bi0.96Sb0.04)2Se2.7Te0.3 crystal was reduced by a factor of ~ 8.0 compared to pristine BiSe3. Additionally, the power factor and figure of merit of the (Bi0.96Sb0.04)2Se2.7Te0.3 compound improved by 3 times and 1.2 times, respectively. Theoretical studies using density functional theory (DFT) supported these experimental findings, showing that substituting Sb in Bi2Se3 enhances its electrical properties.