Sn Substitution Research Articles

Mechanical, optical and high-temperature magnetic properties of Sn-substituted Mg–Zn ferrites

ABSTRACT Sn-substituted Mg–Zn ferrites (0 ≤ x ≤ 0.10) have been synthesized using conventional ceramic technique and the mechanical, optical and high-temperature magnetic properties were studied. The formalism of elastic constants was assessed based on FTIR data. The mechanical stability was confirmed from the obtained values of stiffness constants. The bulk modulus, shear modulus and Young’s modulus have been estimated for different Sn concentrations. The Poisson’s ratio and Pugh ratio confirmed the brittleness character of the studied compounds. The Debye temperature was also calculated. The optical band gap has been calculated from diffuse reflectance spectra. The magnetization curves measured at different temperatures revealed the significant effect of temperature on the magnetic properties of the considered compositions. A second-order phase transition of ferrimagnetic to paramagnetic phase was observed in temperature-dependent magnetization vs. applied field and magnetic moment curves. The Curie temperature was observed to decrease owing to Sn substitution.

Evidence for a Solid-Electrolyte Inductive Effect in the Superionic Conductor Li10Ge1-xSnxP2S12.

Strategies to enhance ionic conductivities in solid electrolytes typically focus on the effects of modifying their crystal structures or of tuning mobile-ion stoichiometries. A less-explored approach is to modulate the chemical bonding interactions within a material to promote fast lithium-ion diffusion. Recently, the idea of a solid-electrolyte inductive effect has been proposed, whereby changes in bonding within the solid-electrolyte host framework modify the potential energy landscape for the mobile ions, resulting in an enhanced ionic conductivity. Direct evidence for a solid-electrolyte inductive effect, however, is lacking—in part because of the challenge of quantifying changes in local bonding interactions within a solid-electrolyte host framework. Here, we consider the evidence for a solid-electrolyte inductive effect in the archetypal superionic lithium-ion conductor Li10Ge1–xSnxP2S12. Substituting Ge for Sn weakens the {Ge,Sn}–S bonding interactions and increases the charge density associated with the S2– ions. This charge redistribution modifies the Li+ substructure causing Li+ ions to bind more strongly to the host framework S2– anions, which in turn modulates the Li+ ion potential energy surface, increasing local barriers for Li+ ion diffusion. Each of these effects is consistent with the predictions of the solid-electrolyte inductive effect model. Density functional theory calculations predict that this inductive effect occurs even in the absence of changes to the host framework geometry due to Ge → Sn substitution. These results provide direct evidence in support of a measurable solid–electrolyte inductive effect and demonstrate its application as a practical strategy for tuning ionic conductivities in superionic lithium-ion conductors.

Ultrasensitive yttrium modified tin oxide thin film based sub-ppb level NO2 detector

Considering the adverse effect of rising air pollution on environment and human health, highly selective and trace level sensors are needed. Herein, yttrium (Y) incorporated tin oxide (SnO2) thin film gas sensors have been developed for sub-ppb level detection of NO2 at room-temperature. The undoped and Y-doped (1, 3 and 5 wt%) thin films have been prepared via electron beam deposition technique. The XPS studies confirmed the substitution of Sn with Y in SnO2 lattice. The morphological and structural characterizations reveal smooth and crystalline thin films, while Raman and PL spectroscopic studies confirm the presence and growth of oxygen vacancies (OVs), specifically in-plane OVs, in doped samples. Moreover, narrowing of electron absorption spectra in doped samples implied the formation of mid-gap states in energy bandgap of SnO2 leading to enhanced electron transfer. The 3 wt% Y-doped SnO2 sensor exhibited excellent sensing response with high selectivity towards NO2 in 15–240 ppb range. The sensors also showed high stability and repeatability along with humidity insensitivity. Notably, the sensor was observed to be highly sensitive to 0.6 ppb NO2 exhibiting a 26 % response along with response/recovery time of 4/2 min. The improved sensing characteristics have been ascribed to reduced crystallite size, elevated in-plane OVs, enhanced charge transfer and increased specific surface area due to Y integration.

Newly Synthesized Ta‐Based MAX Phase (Ta1−xHfx)4AlC3 and (Ta1−xHfx)4Al0.5Sn0.5C3 (0 ≤ x ≤ 0.25) Solid Solutions: Unravelling the Mechanical, Electronic, and Thermodynamic Properties

Investigation of the mechanical, electronic, and thermodynamic properties of recently synthesized (Ta1−xHfx)4AlC3 and (Ta1−xHfx)4Al0.5Sn0.5C3 (0 ≤ x ≤ 0.25) solid solutions is conducted using density functional theory for the first time. The computed lattice constants are in good agreement with prior results. The calculated stiffness constants are used to check the mechanical stability of the studied compositions. The bulk modulus (B), shear modulus (G), and Young's modulus (Y) are found to be influenced by Hf and Sn substitution. The titled solid solutions are brittle in nature. The 3D presentations of elastic moduli and elastic anisotropy factors are used to disclose the anisotropic mechanical features of the considered compositions. The electronic band structure, density of states, and charge density mapping (CDM) show the metallic nature, the contribution from different states to electronic conductivity, and atomic bonding characteristics. The electronic band structure and CDM are also used together to investigate the change in bonding strength due to Hf and Sn substitutions. The Debye temperature (ΘD), minimum thermal conductivity (Kmin), Grüneisen parameter (γ), and melting temperature (Tm) of the studied solid solutions are estimated and analyzed. A good correlation is found between the mechanical and thermodynamic properties.

Improved performance of InGaN/GaN LED by optimizing the properties of the bulk and interface of ITO on p-GaN

Indium Tin Oxide films were deposited directly on p-type Gallium Nitride film using the electron beam deposition method at different substrate temperatures from 25 °C to 550 °C. The structural, optical and Hall measurements represent a direct correlation of ITO properties with the substrate temperature during deposition. The substrate temperature of 450 °C produces the best ITO/p-GaN properties for the InGaN/GaN Light Emitting Diode performance, which outperforms the 550 °C device, although the latter exhibits better optical characteristics. At 100 mA, the 450 °C LED exhibits the highest power efficiency of 9.32 mW with an operation voltage of 6.96 V. X-ray Photoemission Spectroscopy measurement shows that substitution of Sn4+ occurs inside the In2O3 structure, which reaches its limit at the 450 °C substrate temperature. This result manifests the crucial role of the surface chemistry effect on the current injection into the LED. Additionally, the band offset of ITO/p-GaN interface data shows that the interface of the 450 °C sample exhibits the highest conduction band offset of 1.93 eV. For the metal/ITO junction, the 450 °C sample experiences the lowest Conduction Band Maximum of 0.69 eV, which ultimately helps to enhance the carrier injection from the anode part in the device.

Effects of Sn4+ doping and oxygen vacancy on magnetic and electrical properties of yttrium iron garnet prepared by sol-gel method

Sn-substituted yttrium iron garnet samples, Y3Fe5-xSnxO12 (x = 0–0.1, step 0.02) were prepared using a citrate sol–gel method and followed by a sintering process. Synchrotron X-ray diffraction (SXRD), X-ray absorption near edge structure (XANES), scanning electron microscope (SEM) and Fourier infrared spectroscopy (FTIR) measurements were used to investigate the structure parameters, valence state of Fe, oxygen vacancies and lattice distortion in the samples. The magnetic properties of the samples were measured with the SQUID and VSM equipments. The Sn substitution and oxygen vacancies cause the transformation of Fe3+ to Fe2+ which leads to the decrease of Curie temperature and slight increase of saturation magnetization. Temperature dependence of the resistivity in the range of 300–573 K was investigated to elucidate the conduction mechanism in the samples. The resistivity of the sol-gel derived samples was found to be nine orders of magnitudes lower than the value for the bulk sample prepared by flux-grown method. The effects of Fe2+ centers, lattice dislocation, porosity and grain boundary on the resistivity are discussed. This study indicates that Sn-substituted yttrium iron garnets are good candidates for sensor elements which operate based on electrical signals.

N-type Sn substitution in amorphous IGZO film by sol-gel method: A promoter of hall mobility up to 65 cm2/V•s

Indium gallium zinc oxide (IGZO) thin films with various tin (Sn) substitution contents were prepared on the glass substrate by using sol-gel spin coating. After Sn-doped IGZO precursor coatings were calcined at 550°C for 1 hr, the optical and electrical properties of IGZO thin films were characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible spectroscopy (UV-Vis), Hall effect measurement, and X-ray photoelectron spectroscopy (XPS). With the chemical route, the film composition in the form of InGa(Zn1-xSnx)O4 (Sn-x-IGZO) can be well controlled to study the effect of Sn substitution. The results showed that all Sn-IGZO thin films were amorphous, had optical transmittance above 86%, and band-gap of 3.60-3.73 eV. The Sn-0.1-IGZO films with 89% optical transmittance had a carrier concentration of 3.48×1015 cm-3, mobility of 65 cm2/V•s, and electrical conductivity of 4.30×10-2 S/cm, where there was the 15-fold increase in mobility and 2,100-fold increase in conductivity, as compared to the undoped IGZO. A well consistent defect mechanism is proposed to explain the contradiction for more oxygen vacancies at higher Sn4+ content in equations.

P.091 Neurogenetics of attractor dynamic patterns associated with obsessive-compulsive symptoms in healthy children

Sn-substituted yttrium iron garnet samples, Y3Fe5-xSnxO12 (x = 0–0.1, step 0.02) were prepared using a citrate sol–gel method and followed by a sintering process. Synchrotron X-ray diffraction (SXRD), X-ray absorption near edge structure (XANES), scanning electron microscope (SEM) and Fourier infrared spectroscopy (FTIR) measurements were used to investigate the structure parameters, valence state of Fe, oxygen vacancies and lattice distortion in the samples. The magnetic properties of the samples were measured with the SQUID and VSM equipments. The Sn substitution and oxygen vacancies cause the transformation of Fe3+ to Fe2+ which leads to the decrease of Curie temperature and slight increase of saturation magnetization. Temperature dependence of the resistivity in the range of 300–573 K was investigated to elucidate the conduction mechanism in the samples. The resistivity of the sol-gel derived samples was found to be nine orders of magnitudes lower than the value for the bulk sample prepared by flux-grown method. The effects of Fe2+ centers, lattice dislocation, porosity and grain boundary on the resistivity are discussed. This study indicates that Sn-substituted yttrium iron garnets are good candidates for sensor elements which operate based on electrical signals.

The effect of vacancy-defects on the magnetic properties of ZnSn1−xVxAs2: An ab initio study

This paper presents the results of first-principle calculations of the magnetic properties of vanadium-doped and a vacancy-defected chalcopyrite semiconductor ZnSnAs2. It was shown that adding a transition element contributes to the magnetization of ZnSnAs2. The calculations for a number of supercells showed that a ferromagnetic spin ordering is favorable when V substitutes Sn. Besides, the Zn, Sn and As vacancies affect the magnetization. While V(Sn) substitution of the vacancies strengthens magnetization, a slight weakening of the magnetization occurs due to the arsenic atoms. Four As atoms chemically bonded to V dopant were found to be most contributive.

Enhanced cycling stability of Sn-doped Li[Ni0.90Co0.05Mn0.05]O2 via optimization of particle shape and orientation

Ni-rich Li[NixCoyMn1−x−y]O2 (x ≥ 0.8) cathodes suffer from structural degradation and capacity fading owing to the microcracks generated by abrupt volume contraction in the deeply charged state. To resolve this problem, the substitution of Ni by Sn in Li[Ni0.90Co0.05Mn0.05]O2 is proposed. Li[Ni0.897Co0.05Mn0.05Sn0.003]O2 (Sn-NCM90) has a unique microstructure in which the primary particles are oriented along the radial direction. This radial alignment, combined with the (001) crystallographic texture, suppresses microcrack formation and propagation by effectively relieving an internal strain in the deeply charged state. The microstructure-modified Sn-NCM90 cathode delivers a discharge capacity of 224.3 mAh g−1 and exhibits a capacity retention of 92.9% after 100 cycles at 4.3 V and 82.9% at 4.4 V. The proposed Sn substitution method shows that appropriate microstructural modification of the cathode can improve the cycling stability of Ni-rich layered cathodes.

Structural, dielectric, ferroelectric and tuning properties of Pb-free ferroelectric Ba0.9Sr0.1Ti1-xSnxO3

A series of Pb-free ferroelectric materials Ba0.9Sr0.1Ti1-xSnxO3 (BSTS-x) with 0 ≤ x ≤ 0.15 was successfully prepared via solid-state reaction method. The effect of Sn substitution on the crystal structure, microstructure, dielectric behavior, ferroelectric and tunable features of BSTS-x ceramics were systematically investigated. Room temperature (RT) x-ray diffraction (XRD) analysis using the Rietveld refinement method reveals that all the synthesized BSTS-x ceramics were well crystallized into single perovskite structure. The results show a tetragonal phase for 0.00 ≤ x ≤ 0.02, which evolves to orthorhombic and tetragonal coexisting phases for 0.05 ≤ x ≤ 0.07. The composition x = 0.10 showed a mixture of tetragonal, orthorhombic and rhombohedral phases at RT, while a single cubic phase is observed for x = 0.15. The crystal phases determined by XRD were confirmed by Raman spectroscopy. Enhanced dielectric permittivity with a maximum value of ε'~35000 is observed for x = 0.10 at RT. The ferroelectric behavior of BSTS-x ceramics was investigated through polarization hysteresis loops and tunability measurements. High tunability of 63% at RT and under the low DC-applied electric field of 1.40 kV/cm is achieved for x = 0.10.

Study the magnetic and dielectric properties of Sn substituted nickel–cobalt ferrite synthesized by auto combustion method

Nickel–cobalt ferrites with the stoichiometry of Ni0.4Co0.6–xSnxFe2O4 (where, x = 0, 0.02, 0.04, 0.06, 0.08, and 0.10) have been synthesized by the auto combustion method. The X-ray diffraction (XRD) pattern discloses a single-phase spinel structure, and the crystallite sizes of the nanoparticles are estimated at about 12–28 nm. The diffraction peak shifts towards the lesser angle and the lattice parameter slightly improves with the Sn substitution. The surface morphology and elemental composition are examined by the scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX), respectively. At room temperature, the bulk density, grain size, and coercivity are increased with the Sn substitution. The hysteresis loops of this sintered specimen display an improved magnetic behavior at ambient temperature. The saturation magnetization increases initially and reaches to the maximum at x = 0.02 (78.05 emu/g) then decreases with higher Sn substitution. All the sintered species retain in the multi magnetic domain. Prepared samples demonstrate a slight reduction both in dielectric constant (e׳) and loss tangent (tanδ) with an increment of the Sn substitution. The proposed work is expected to open the possible emersion of the ferrite in the high-frequency applications.

Visible light-driven photocatalytic dye degradation under natural sunlight using Sn-doped CdS nanoparticles.

Herein, cadmium sulfide (CdS) nanoparticles (NPs) and different concentrations (1-5 and 10 wt %) of Sn-doped CdS NPs were prepared by a chemical precipitation method using PVP as a capping agent. The synthesized NPs were characterized using various characteristic techniques such as XRD, SEM, TEM, Raman spectroscopy, UV-Vis, and photoluminescence to investigate structural, morphological, and optical properties. Optical band gap of CdS has been tuned by substitution of Sn with different concentrations. Pure CdS and Sn-doped CdS NPs were used for the photocatalytic degradation of methylene blue (MB) dye under direct sunlight irradiation. The photocatalytic activity of the Sn-doped CdS NPs is attributed to the interface actions between Sn and CdS, which significantly decreases the recombination of a photogenerated electron-hole pair. The degradation efficiencies were found to be 91.39% and 97.56% within 180 min for pure CdS and Sn-doped CdS NPs, respectively. Among the catalysts, 4% Sn-doped CdS NPs exhibit best photocatalytic degradation efficiency after 180 min of irradiation.

Enhanced elastocaloric effect and mechanical properties of Gd-doped Ni–Mn–Sn-Gd ferromagnetic shape memory alloys

The effect of Gd substitution for Sn on martensitic transformation (MT) temperature, microstructure, elastocaloric effect (eCE) and mechanical properties of Mn49Ni41Sn10 ferromagnetic shape memory alloy has been systematically investigated. These alloys undergo MT from L21 austenite to 5 M martensite during the cooling process. MT temperature can be tuned to the vicinity of room temperature by alloying Gd. The substitution of Gd for Sn introduces γ phase (Gd-rich second phase in Gd-doping alloys), and the volume fraction of the γ phase increases with the increase of Gd content from 0.3 at.% to 0.9 at.%. Among these alloys, Mn49Ni41Sn9.4Gd0.6 alloy shows prominent eCE and stable superelasticity, making it a promising candidate for the elastocaloric cooling application. A large adiabatic temperature change of −11.4 K is obtained by the stress (500 MPa) removal, and a constant temperature change of −9.6 K shows no apparent degradation under the compressive stress of 400 MPa during 200 cycles for this alloy. The underlying mechanism of the enhanced eCE and mechanical properties is also revealed.

The effects of Ca, Zr and Sn substitutions into a ternary system of BaTiO3–BaSnO3–BaZrO3 towards its dielectric and piezoelectric properties: a review

The discovery of the dopant effects on BaTiO3 has attracted great interest after a compound of 50(BaTi0.8Zr0.2O3)–50(Ba0.7Ca0.3TiO3) system exhibited extraordinarily high piezoelectric properties (d33 > 600 pC/N). Recently, modifications made on the BaTiO3-based piezoelectric materials, particularly at the A-site, have gained the most attention due to the existence of the morphotropic phase boundary (MPB) region. In this paper, we reviewed several dopants that have been extensively used to enhance the piezoelectric and dielectric properties of a BaTiO3 such as Sn and Zr. A ternary triangle of BaTiO3–BaSnO3–BaZrO3 is used to evaluate the correlations between the changes in the Sn- and/or Zr-doped BaTiO3 piezoelectric ceramic properties. The structural changes that have been affected by the dopant contents were also comprehensively reviewed. There is clear evidence that the dopants significantly affect the intrinsic properties of the BaTiO3-based ceramic materials. The dielectric constant er value increases from 1900 to ~ 6000 at room temperature, while the piezoelectric constant d33 value is also increased from 191 pC/N to ~ 600 pC/N. All the compositions described in this review were prepared by using a conventional solid-state route.

Compositional Optimization and Structural Properties of the Filled Skutterudite Smy(FexNi1−x)4Sb11.5Sn0.5

A compositional and crystallographic study was carried out on the Smy(FexNi1−x)4Sb11.5Sn0.5 filled skutterudite system (0.40 ≤ x ≤ 0.80) with the aim to determine the equilibrium Sm filling fraction (y) within the considered x range. The relevance of the material lies in its potential thermoelectric properties: in analogy with similar skutterudites systems, these features should in fact result as being improved with respect to the ones of the corresponding Sn-free system thanks to the partial substitution of Sn for Sb, which is expected to lower the phonon thermal conductivity. The results of Rietveld refinements allowed us to study the skutterudite structural properties and to discuss them, adopting a comparative approach with respect to the ones of the Sn-free system Smy(FexNi1−x)4Sb12. Relying on the refined Sm occupancy factors, the p/n crossover is shown to be located at x ~ 0.53, meaning that the introduction of Sn induces an enlargement of the p-region; moreover, at variance with the Sn-free system, the coefficient of thermal expansion does not show any significant mismatch between n- and p-compositions, which should ensure a prolonged lifetime of a device made of n- and p-legs that both derive from the studied system.

Effect of Ag incorporation on structure and optoelectronic properties of (Ag1−xCux)2ZnSnSe4 solid solutions

The performance of $\mathrm{C}{\mathrm{u}}_{2}\mathrm{ZnSnS}{\mathrm{e}}_{4}$ solar cells is presently limited by low values of open-circuit voltage which are a consequence of strong band tailing and high level of nonradiative recombination. Recently, the partial substitution of Cu, Zn, and Sn by other elements has shown the potential to overcome this limitation. We explored the structural changes and the effect on the optoelectronic properties of the partial substitution of Cu with Ag in $\mathrm{C}{\mathrm{u}}_{2}\mathrm{ZnSnS}{\mathrm{e}}_{4}$. This paper clarifies the crystal structure of ${(\mathrm{A}{\mathrm{g}}_{1\ensuremath{-}x}\mathrm{C}{\mathrm{u}}_{x})}_{2}\mathrm{ZnSnS}{\mathrm{e}}_{4}$ solid solution series, deducing possible cationic point defects and paying special attention to the presence of Cu/Zn disorder with a combination of neutron and x-ray diffraction. The optoelectronic properties of the solid solution series are assessed using reflection and quantitative photoluminescence spectroscopy, which allows us to estimate the fraction of nonradiative recombination, which would contribute to the open-circuit voltage loss in devices. The results strongly suggest Ag incorporation as a promising route to eliminate Cu/Zn disorder and to reduce nonradiative recombination losses in $\mathrm{C}{\mathrm{u}}_{2}\mathrm{ZnSnS}{\mathrm{e}}_{4}$.

Sn Substitution by Ge: Strategies to Overcome the Open-Circuit Voltage Deficit of Kesterite Solar Cells

Current state-of-the-art Cu2ZnSn(S,Se)4 kesterite solar cells are limited by low open-circuit voltages (VOC). In order to evaluate to what extent the substitution of Sn by Ge is able to result in h...

Theoretical analysis of thermoelectric performance in p-type CoSb3 based skutterudite by simultaneous partially void filling and Sn substitution

The investigation of CoSb3-based skutterudites is an important research area. Filling their structural voids and/or doping them upon substitution either at the metal or at the pnicogen sites improves the point defect scattering mechanism and enhance the thermoelectric figure of merit (ZT), thus resulting in a higher Seebeck coefficient and electrical conductivity and a lower thermal conductivity. In this work we analyze the effect of Sn substitution on the structural, electronic and thermoelectric properties of doped and partially filled CoSb3 (Ba0.5Co8Sb24-xSnx), where (x = 0, 1, 2, 3 and 4). Our calculations are performed within the fully potential-linearized augmented plane wave method (FP-LAPW) using a semi-classical Boltzmann transport theory. The theoretical analysis show that the charge balance of Ba0.5Co8Sb24-xSnx strongly depends on the substitution configuration. The Ba0.5Co8Sb23Sn composition is the most stable in terms of energy. When we examine the effect of Sn substitution on the electronic and thermoelectric properties, we find that the electronic properties are moderate and thermoelectric performance is improved. That is, the estimated dimensionless electronic figure of merit (ZTe) is approximately 0.67 at T = 500K for Ba0.5Co8Sb23Sn; ranking this material as a promising candidate for thermoelectric applications.

Enhanced Thermoelectric Transport Properties of <i>n</i>-type InSe by Sn doping

Layered post transition metal chalcogenides such as SnSe, SnSe<sub>2</sub>, In<sub>2</sub>Se<sub>3</sub>, and In<sub>4</sub>Se<sub>3</sub> have attracted attention as promising thermoelectric materials due to their intrinsically low lattice thermal conductivities. Recently, <i>n</i>-type indium selenide (InSe) based materials have also been suggested as good candidates for thermoelectric materials by optimizing their electrical properties, i.e., increasing carrier concentration. Here, we report enhancement of the thermoelectric properties of <i>n</i>-type InSe by Sn substitutional doping at the In site. A series of In<sub>1-x</sub>Sn<sub>x</sub>Se for x = 0, 0.03, 0.05, 0.15 and 0.2 was examined. The carrier concentration and electrical conductivity increased due to the Sn substitution, since Sn behaves as a shallow electron donor in InSe, while the Seebeck coefficient decreased moderately. In addition, it was found that effective mass was increased by more than 10 times by Sn doping. As a result, the power factor was enhanced from 0.07 mW/mK<sup>2</sup> to 0.13 mW/mK<sup>2</sup> at 800 K. The total thermal conductivity was unchanged despite Sn doping because the electrical contribution to the total thermal conductivity was very small. Consequently, Sn doping in InSe enhanced the dimensionless thermoelectric figure of merit <i>zT</i> from 0.04 to 0.14 at 800 K, mainly due to enhanced electrical properties.