Ternary Crystals Research Articles

Design and simulation of high-sensitivity refractometric sensors based on defect modes in one-dimensional ternary dispersive photonic crystal

Photonic crystals are widely used in sensors, lasers, optical wavelength filters, and dispersion compensations used in optical communication networks. We propose to exploit the defect modes of one-dimensional ternary photonic crystals based on silicon, analyte, and silica layers for a refractive index sensor. The defect modes are created by inserting an analyte layer in the middle of the structure between two adjacent silica and silicon layers. Exploiting the defect modes in the transmission spectrum leads to hypersensitivity. The results show that the thicknesses of the layers and defect part are, respectively, about 155, 700, 155, and 1200 nm in optimum conditions. Our optimum structure is about 11 µm long, and sensitivity of this structure is more than 450 nm/RIU and 600 nm/RIU for the perpendicular light incident and incident angle of 45°, respectively. The effect of dispersion is investigated on the sensor operation, too. Numerical simulations exhibit that sensitivity is decreased to 410 nm/RIU for incident perpendicular rays. Also, the optimum thickness of the defect layer is changed significantly when considering the dispersion effects, so dispersion plays a significant role in the proposed sensor.

Large Piezoelectricity in Ternary Lead‐Free Single Crystals

AbstractSince industry‐standard piezoelectric materials, such as lead zirconium titanate ceramics, contain toxic lead, a rapid surge in research on lead‐free piezoelectric materials is occurring due to concerns over environmental safety and human health. A ternary lead‐free (Na0.5Bi0.5)TiO3‐BaTiO3‐(K0.5Na0.5)NbO3 single crystal with a large field induced strain of ≈0.9% and a giant piezoelectric coefficient d33 of 840 pC N−1 at room temperature is reported. It is revealed that the electric‐field‐induced phase transition and phase boundary between energetically comparable polar states (i.e., R3c and P4mm) play an important role in achieving the ultrahigh piezoelectricity. Transmission electron microscopy and scan probe microscopy are employed to verify the weak‐polar ferroelectric R3c and P4bm structure in the ground state. These unprecedentedly high piezoelectric properties make lead‐free ternary single crystals a leading candidate for piezoelectric‐based device applications, especially toward the era of smart homes and implantable medical devices.

Analysis of Temperature Sensors Based on Ternary One Dimensional Photonic Crystals with Double Defects

Based on the transfer matrix method (TMM), the interaction of electromagnetic waves in ultraviolet (Uv), visible and Infrared (IR) spectra with ternary one-dimensional photonic crystals with different double defects, has been theoretically studied. The multilayer system has been taken as temperature dependent. The numerical results showed that the number of photonic band gap (PBG) was increased by increasing the degree of temperature. The variation of temperature, the thickness of the second layer and both the type and the thickness of the second defect caused shifting of the photonic ban gaps to higher wavelengths which can be exploited in the design of temperature sensors.

Study on the low-frequency forbidden transmission properties of one-dimensional ternary solid-fluid sonic crystals by FEM

Based on the finite element method (FEM), an acoustic transmission model of onedimensional ternary solid-fluid sonic crystals under the condition of oblique incidence is established. Transmission spectra of acoustic waves with different incident angles and frequencies in sonic crystals are calculated. The results show that two broadband forbidden band gaps exist in the low frequency range within two separated incident angle ranges for the ternary structure, which has one more band gap than the binary solid-fluid structure. By adjusting the solid filling fraction, period and lattice constant of the ternary structure, the angle widths of these two band gaps can be effectively regulated. This work will be of great significance to the design of underwater low-frequency acoustic filters.

The Influence of Electron Irradiation on the Dielectric Characteristics of Single Crystals of AgGaSe2

The influence of various doses of electron irradiation on the dielectric permeability and specific conductance of ternary nonlinear optical crystals of AgGaSe2 at various frequencies of the measuring field in a range of temperatures of 100–300 K is studied. It is found that the irradiation of single crystals leads to a decrease in the values of dielectric permeability and a significant increase in conductance. It is shown that dielectric permeability and conductance increase with the growth in temperature. It is found that the presence of several types of conductance is characteristic for the crystals of AgGaSe2. Substantial frequency dispersion of the dielectric properties of the studied crystals is found.

Dielectric and piezoelectric properties of Pb[(Mg1/3Nb2/3)0.52(Yb1/2Nb1/2)0.15Ti0.33]O3 single-crystal rectangular plate and beam mode transducers poled by alternate current poling

The dielectric, piezoelectric and physical properties of the [001]-oriented rectangular plate and beam mode of Pb[(Mg1/3Nb2/3)0.52(Yb1/2Nb1/2)0.15Ti0.33]O3 (PMN-PYbN-PT) ternary single crystals (SC) poled by alternate current poling (ACP) were investigated. The dielectric permittivity and average piezoelectric coefficient d33 were 6800 and 2490 pC/N, respectively, for the rectangular plate sample after ACP, which were 31% and 41% larger than those of the same sample after conventional direct current poling. The highest value of d33 reached 2750 pC N−1. The dielectric loss was reduced by 31%; nevertheless, the d33 improved after ACP. The beam mode electromechanical coupling factor () was 91% by using ACP, showing the highest value among all relaxor-PT SC systems reported so far. The regular periodic stripe domains were observed in ACP samples, showing high domain wall density and uniform domain size. This work demonstrates that the high performance after ACP is an effective method of improving the relaxor-PT SC transducers.

An Approach to Optimize the Thermoelectric Properties of III-V Ternary InGaSb Crystals by Defect Engineering via Point Defects and Microscale Compositional Segregations.

Thermoelectric power generators require semiconductor materials with controlled phonon and free charge carrier transport properties. This could be achieved by changing their molecular and lattice dynamics through introducing/controlling structural imperfections (defects engineering). The structural imperfections such as point defects and compositional segregations in a multicomponent alloy are observed experimentally, and their impact on electron and phonon transport properties was explained. The thermoelectric properties of a III-V ternary alloy InGaSb was improved by the presence of point defects and compositional segregations. The compositions were segregated randomly, and they had a major impact on the phonon contribution to the thermal conductivity. The point defects affected electrical resistivity, and the Seebeck coefficient was influenced by carrier concentration. The figure of merit (ZT) of In0.95Ga0.05Sb is enhanced to 0.62 at 573 K, and it is the highest among any other reported values of binary/ternary III-V semiconductor alloys. The enhancement in the ZT of InGaSb from the viewpoints of point defects and compositional segregations are explained. This experimental defect engineering study could be helpful to understand and improve the thermoelectric properties of many other crystalline materials.

Structures and pyroelectric properties for [111]‐oriented Mn‐doped rhombohedral 0.36PIN‐0.36PMN‐0.28PT crystal

AbstractThe crystal structures, pyroelectric properties, and thermal stability of [111]‐oriented 0.5 mol% Mn‐doped 0.36Pb(In1/2Nb1/2)O3‐0.36Pb(Mg1/3Nb2/3)O3‐0.28PbTiO3 (Mn‐0.36PIN‐0.36PMN‐0.28PT) ternary single crystal were investigated. The temperature dependence of the Raman spectra and dielectric properties revealed that the crystal exhibited a rhombohedral (R) structure at room temperature, and ferroelectric R → tetragonal (T) and ferroelectric T to paraelectric cubic (C) phase transitions at 130 and 175°C respectively. The single crystal had a high remnant polarization of Pr = 38 μC cm–2 and coercive field of EC = 12 kV cm–1 at room temperature and a frequency of f = 100 Hz. The values of Pr and EC decreased with increasing temperature, exhibiting anomalies near their phase‐transition temperatures, which coincided with changes in the Raman spectra and dielectric properties. Furthermore, at 25°C and f = 100 Hz, the single crystal had high pyroelectric coefficients of p = 8.7 × 10−4 C m−2 K−1, figures of merit for the current responsivity of Fi = 3.5 × 10−10 m V−1, the voltage responsivity of Fv = 0.08 m2 C−1, and the detectivity of Fd = 30.1 × 10−5 Pa−1/2. These values were weakly dependent on temperature below 120°C. In addition, the room‐temperature pyroelectric coefficients of the ternary single crystal maintain over 83% of the original value at thermal annealing temperatures below 120°C. These outstanding pyroelectric properties, together with high thermal stability, indicate that [111]‐oriented rhombohedral Mn‐0.36PIN‐0.36PMN‐0.28PT ternary single crystal is a new potential candidate for infrared detection applications.

Properties of ternary photonic crystal consisting of dielectric/plasma/dielectric as a lattice period

Ternary photonic crystals have shown a superior performance over the binary ones. In this work, a ternary photonic crystal which has the structure dielectric/plasma/ dielectric is considered. Transmission through the proposed photonic crystal at oblique incidence on a specific PC structure is analyzed using the transfer matrix technique. The effect of the plasma layer of the photonic band gap is investigated. The use of the proposed photonic crystal as an optical sensor for detection of small changes within the plasma electron density or the index of refraction of the dielectric layers is investigated.

Design of one dimensional refractive index sensor using ternary photonic crystal waveguide for plasma blood samples applications

One dimensional ternary photonic crystal based refractive index sensor is numerically proposed for the blood plasma sensing applications. It is achieved by introducing the defects or cavity cell, where the blood samples are infiltrated and surrounded by the graphene layers at the middle region of the ternary structures. Introduction of the graphene layer is to avoid the change in blood sample characteristics due to few ambient factors. The whole structure is then tuned to observe the transmittance spectrum over the infrared region (800 nm–1200 nm). It is noticed that the resonance spectral shift occurs for variation of the blood plasma samples as 10 g/l, 20 g/l, 30 g/l, 40 g/l & 50 g/l. These spectral shifts report the device sensitivity and it is optimized for different filling factor of nanocomposite material and different thickness of the graphene coating.

Synthesis of Large‐Area Atomically Thin BiOI Crystals with Highly Sensitive and Controllable Photodetection

AbstractCompared to the most studied 2D elements and binary compounds, ternary layered compounds with more adjustable physical and chemical properties have exhibited potential applications in electronic and optoelectronic devices. Here, 2D ternary layered BiOI crystals are synthesized first with a domain size up to 100 µm via space‐confined chemical vapor deposition. The photodetectors based on the as‐grown BiOI nanosheets demonstrate high sensitivity to 473 nm light. The Ion/Ioff ratio and detectivity of BiOI photodetectors can reach up to 1 × 105 and 8.2 × 1011 Jones at 473 nm, respectively. Particularly, the contact and dark current of the photodetectors can be controlled by 254 nm ultraviolet light irradiation due to the introduction of oxygen vacancies. The facile synthesis of large‐area atomically thin BiOI and its controllable performance by ultraviolet light irradiation suggest that 2D BiOI crystal is a promising material for fundamental investigations and optoelectronic applications.

Analysis of photonic band gap in photonic crystal with epsilon negative and double negative materials

The transmission properties of one-dimensional binary and ternary photonic crystals are theoretically investigated using transfer matrix method. The binary structure is composed of alternate layers of epsilon-negative and double-negative materials. The photonic band gap is analyzed by changing the permeability of epsilon negative material. It is found that the width of the photonic band gap increases with the increase of the permeability of epsilon negative material. It is also analyzed by varying the ratio of the plasma frequency to the resonance frequency in both materials. The width of the band gap increases with the increase of this ratio. A wider band gap of width 10.8 GHz can be achieved in ternary structures which contain an additional epsilon negative layer. It can be utilized in the microwave bands of X band, a portion of C band and Ku band as a double negative medium. A special kind of photonic band gap is found in both the binary and ternary structures.

The reflection and absorption characteristics of one-dimensional ternary plasma photonic crystals irradiated by TE and TM waves

The present study is aimed to investigate the reflection and absorption of electromagnetic waves propagating through one-dimensional ternary plasma photonic crystals (TPPCs) using transfer matrix method. Two different configurations of ternary plasma photonic crystal structures are considered. In the first configuration, unit cells contain plasma1-dielectric-plasma2 layers (P1DP2); while the second configuration is composed unit cells included of dielectric1-plasma-dielectric2 layers (D1PD2). In this structure the plasma is considered cold collisional.The effects of normal and oblique incidence of the monochromatic electromagnetic waves on photonic band gap of the TPPC, will be presented. In addition, the reflectance and absorbance coefficients of electromagnetic wave incident to the TPPC have been calculated. We will show plasma photonic crystal presented in this work, has the great potential to change the optical properties. By varying different parameters, the reflection, absorption and number and width of band gaps change. The results indicate that photonic band gap can be tuned in a desirable frequency range by adjusting the properties of plasma such as collision frequency and plasma frequency and structural characteristics of the TPPC including plasma-filling factor, the number of the cells and also permittivity of dielectric layer.

Multi-loop node line states in ternary MgSrSi-type crystals

Node line band-touchings protected by mirror symmetry (named as m-NLs), the product of inversion and time reversal symmetry S = PT (named as s-NLs), or nonsymmorphic symmetry are nontrivial topological objects of topological semimetals in the Brillouin Zone. In this work, we screened a family of MgSrSi-type crystals using first principles calculations, and discovered that more than 70 members are node-line semimetals. A new type of multi-loop structure was found in AsRhTi that a s-NL touches robustly with a m-NL at some “nexus point”, and in the meanwhile a second m-NL crosses with the s-NL to form a Hopf-link. Unlike the previously proposed Hopf-link formed by two s-NLs or two m-NLs, a Hopf-link formed by a s-NL and a m-NL requires a minimal three-band model to characterize its essential electronic structure. The associated topological surface states on different surfaces of AsRhTi crystal were also obtained. Even more complicated and exotic multi-loop structure of NLs were predicted in AsFeNb and PNiNb. Our work may shed light on search for exotic multi-loop node-line semimetals in real materials.

Agent-assisted VSSe ternary alloy single crystals as an efficient stable electrocatalyst for the hydrogen evolution reaction

New ternary VSSe alloy single crystals were synthesized and used as an excellent HER electrocatalyst due to the pure conductive phase and abundant active sites.

Decorative near-infrared transmission filters featuring high-efficiency and angular-insensitivity employing 1D photonic crystals

We present a new scheme for visibly-opaque but near-infrared-transmitting filters involving 7 layers based on one-dimensional ternary photonic crystals, with capabilities in reaching nearly 100% transmission efficiency in the near-infrared region. Different decorative reflection colors can be created by adding additional three layers while maintaining the near-infrared transmission performance. In addition, our proposed structural colors show great angular insensitivity up to ±60° for both transverse electric and transverse magnetic polarizations, which are highly desired in various fields. The facile strategy described here involves a simple deposition method for the fabrication, thereby having great potential in diverse applications such as image sensors, anti-counterfeit tag, and optical measurement systems.

A tunable broadband filter of ternary photonic crystal containing plasma and superconducting material

This work reports the optical properties of a one-dimensional (1D) ternary periodic structure composed of a dielectric, magnetized cold plasma (MCP) and superconducting material by using well-known simple transfer matrix method. The MCP has considered right-hand and left-hand polarizations having positive (+ B) and negative (− B) transverse magnetic field, respectively. The transmittance of the ternary photonic crystals is analyzed by varying the angle of incidence, the magnetic field, the electron density of the magnetized cold plasma, the temperature of the superconductor, the thickness of magnetized cold plasma and superconducting material for the right-hand and left-hand polarization structures. The transmittance of the ternary photonic crystal containing dielectric, magnetized cold plasma and superconducting material has tunable broadband and narrowband filters for the left-hand and right-hand polarizations, respectively. The magnetized cold plasma layer in the ternary photonic crystal also played an important role to form the tunable gap due to the transverse magnetic field. The analysis of the transmittance of the ternary photonic crystal containing dielectric, magnetized cold plasma and superconducting materials has shown an innovative idea for the formation of the tunable broadband and the narrowband filters.

Temperature sensor utilizing a ternary photonic crystal with a polymer layer sandwiched between Si and SiO2 layers

Recently, one-dimensional periodic ternary photonic crystals have shown outstanding properties when compared to one-dimensional periodic binary photonic crystals. In this work, a ternary photonic crystal is proposed as a temperature sensor. The structure of the ternary photonic structure is considered Si/polymer/SiO2. The transmission spectra of the proposed ternary photonic structure are studied for different temperatures. It is observed that as the temperature increases, the transmission peak shifts toward higher wavelengths due to thermo-optic and thermal expansion coefficients of the polymer. It is found that the temperature-sensitive transmission peak shift is considerably enhanced due to the insertion of the polymer layer between Si and SiO2 to constitute a ternary photonic crystal.

Analysis of photonic band gaps in metamaterial-based one-dimensional ternary photonic crystals

In the present work, we propose a one-dimensional ternary photonic crystals composed of alternatively stacked dispersive metamaterial layers including double-negative (electric permittivity e 0), and mu-negative material (μ 0) within some frequency ranges. Various types of photonic band gaps including Bragg gaps, zero-permittivity gap, zero-permeability gap, and a special band gap are, respectively, presented and discussed against the periodic number, thickness of dielectric layer, and incident angle. In the case of normal incidence, the band width, position, and transmittance for the Bragg and special band gaps are related to the thickness of each layer and periodic number. Under the oblique incidence (incident angle 0° < θ < 90°) condition, both the zero-permittivity band gap for TM wave and zero-permeability band gap for TE wave are achieved, which are significantly broadened and blue-shifted with respect to the increase in incident angle. As such, the incident angle-dependent Bragg band gaps and special band gap are also exhibited by selecting TE- and TM-polarized waves, respectively.

Systematic synthesis of a 6-component organic-salt alloy of naftopidil, and pentanary, quaternary and ternary multicomponent crystals.

The single-crystal X-ray structure of a 6-component organic-salt alloy (hexanary) of naftopidil (1) (an active pharmaceutical ingredient) with benzoic acid (2) and four different hydroxy-substituted benzoic acids, i.e. salicylic acid (3), 2,3-di-hydroxybenzoic acid (4), 2,4-di-hydroxybenzoic acid (5) and 2,6-di-hydroxybenzoic acid (6), is reported. The hexanary assembly originates from the observation that the binary salts of naftopidil with the above acids are isostructural. In addition to the 6-component solid, we also describe five 5-component, ten 4-component, and ten 3-component organic-salt alloys of naftopidil (1) with carboxylic acids (2)-(6). These alloys were obtained from different combinations of the acids with the drug. The synthetic design of the multicomponent organic alloys is based on the rationale of geometrical factors (shape and size) and chemical interactions (hydrogen bonds). The common supramolecular synthon in all these crystal structures was the cyclic N+-H⋯O- and O-H⋯O hydrogen-bonded motif of (9) graph set between the 2-hy-droxyammonium group of naftopidil and the carboxyl-ate anion. This ionic synthon is strong and robust, directing the isostructural assembly of naftopidil with up to five different carboxylic acids in the crystal structure together with the lower-level multicomponent adducts. Solution crystallization by slow evaporation provided the multicomponent organic salts and alloys which were characterized by a combination of single-crystal X-ray diffraction, powder X-ray diffraction, NMR and differential scanning calorimetry techniques.