Te Samples Research Articles

Multiple defect states engineering towards high thermoelectric performance in GeTe-based materials

GeTe is a promising material for thermoelectric (TE) applications. However, its low Seebeck coefficient and high thermal conductivity in the mid-temperature range of 298–550 K have hindered its widespread use in TE devices. In this work, we show that a combination of band engineering, Fermi level tuning, and miscibility gap exploration can significantly improve the energy conversion performance of GeTe. Bi provides the optimized carrier concentration and induces band convergence, while Ga possibly forms a resonant state. The synergistic effects of Bi and Ga significantly improve the Seebeck coefficient from 38 µVK−1 for undoped GeTe to over 120 µVK−1 for Bi and Ga-containing materials at 298 K and provide a high power factor over a wide temperature range. Phonon scattering is strengthened by optimizing the microstructure through Pb-induced spinodal decomposition and enhanced point defect scattering due to increased dopant solubility, resulting in a very low lattice thermal conductivity of about 0.5 Wm-1K−1 at 600 K for the triple-doped samples. The maximum thermoelectric figure of merit ZT was significantly increased to 2.1 at 600 K for the Ge0.87Pb0.05Bi0.06Ga0.02Te sample due to the improved power factor and reduced lattice thermal conductivity. Additionally, the average figure of merit ZTave for this sample achieved a very high value of 1.4 for Ge0.87Pb0.05Bi0.06Ga0.02Te at a temperature gradient of 475 K (Tc = 298 K). The developed material shows great potential for use in energy conversion devices, with an estimated energy conversion efficiency exceeding 17 %.

Negative and persistent photoconductivity in Bi-doped Pb0.5Sn0.5Te epitaxial films

This work presents the investigation of the photoconductivity effect in undoped and doped Pb0.5Sn0.5Te epitaxial films, with bismuth (Bi) atoms, at temperatures of 80 and 300 K. The results indicate that the samples show negative photoconductivity effect (NPC) and persistent photoconductivity (PPC). A detailed study was performed on Pb0.5Sn0.5Te sample doped with 0.15 % Bi, which presented higher photoconductivity amplitude than the other samples, by performing Hall effect and photoconductivity measurements in the temperature range of 80–300 K under dark and illuminated conditions. Using Arrhenius model, trap activation energy was extracted and compared with energies found in literature. From the Hall measurement we found that the NPC effect observed is due to a decrease in the mobility when the sample is illuminated while the carrier concentrations are nearly unaltered. It was also found that Pb0.5Sn0.5Te:Bi presented photoconductivity response for a wide range of wavelengths, indicating that it is potentially interesting for application in optic sensor devices.

Enhancement of the response speed of CIGS-based photodetector by Te-doping

Cu(In,Ga)Se2 (CIGS) based devices are promising candidates for high performance photodetector applications. The present work investigated the effects of Te-doping on the properties of CIGS layers and studied the performance of photodetectors (PDs) fabricated on these films. The films were vacuum evaporated on glass substrates and their morphological, structural and optical properties were evaluated after an annealing step at 550ºC. Morphological data indicated that undoped CIGS films had non-uniform surface features with large grains separated by nanoparticles. Addition of 6.6 % Te improved the morphology and yielded a smoother layer. Further increase in Te concentration showed appreciable reduction in surface feature size and shape. X-ray diffraction patterns showed that increasing the Te amount in CIGS caused a shift in the XRD peaks towards smaller angles pointing to replacement of Se atoms by Te. Peak splitting at higher Te samples suggested a graded structure with Se and Te amounts changing through the thickness of the film. Raman analysis demonstrated formation of CuInGa(Se,Te)2 (CIGST) compound. According to Tauc’s approximation, CIGS films with and without Te atoms possessed two energy band gaps of Eg1 and Eg2 that were in the ranges of 1.10–1.28 eV and 1.16–1.36 eV, respectively. Electrical data obtained from photodetector devices showed a responsivity of 4.44×10−1 A/W and a detectivity of 8.01×107 Jones for Te-free material, while the rise/fall times were measured as 34/148 ms. A much faster response speed of 19/20 ms was reached for devices fabricated on films with 10.2 % Te. This work demonstrated, for the first time, the fabrication low-cost and high-performance metal-semiconductor-metal (MSM) type CIGST-based PDs.

Enhancing n-type PbTe thermoelectric performance through Cd alloying and strategic defects management

The significant performance disparity between n-type and p-type PbTe hinders their commercial viability in thermoelectric (TE) applications. While conventional multi-element alloying has demonstrably improved n-type PbTe thermoelectrics, it introduces stability concerns and cost escalation. Here, we propose a simpler approach utilizing a single isovalent element alloying strategy with Cd and defect management to enhance the TE performance of n-type PbTe. Cd doping widens the bandgap, leading to an increased effective mass and Seebeck coefficient, particularly at higher temperatures due to improved Cd solubility. However, as documented in previous studies on the PbTe-Cd system, Cd introduction can potentially deteriorate TE performance by reducing carrier mobility. To address this, we implemented defect engineering to optimize carrier mobility. A small excess of Pb atoms was introduced to occupy intrinsic Pb vacancies, achieving a remarkable 65.5 % enhancement in carrier mobility. Consequently, the maximum power factor of Cd-alloyed Pb1.01Te samples reaches 31.5 μW cm−1 K−2, marking a significant 69.3 % improvement compared to pristine PbTe. Additionally, the Cd-induced bandgap widening effectively mitigates bipolar diffusion. This, combined with enhanced phonon scattering due to the secondary CdTe phase, results in a 34.3 % decrease in thermal conductivity. By leveraging the multifaceted effects of Cd alloying and defect management, the ZT value of Pb1.01Te-2 %Cd samples reaches 1.35 at 782 K. These findings offer a new perspective on the versatile use of single isovalent element alloying strategy and performance optimization in other TE materials.

Vacancy Suppression and Resonant Level Rendering Extraordinary Power Factor in Sn0.99In0.01Te/Tourmaline Composite.

SnTe, as a potential medium-temperature thermoelectric material, reaches a maximum power factor (PF)usually above 750K, which is not conducive to continuous high-power output in practical applications. In this study, PF is maintained at high values between 18.5 and 25µWcm-1K-2 for Sn0.99In0.01Te-xwt% tourmaline samples within the temperature range of 323 to 873K, driving the highest PFeng of 1.2Wm-1K-1 and PFave of 22.5µWcm-1K-2, over 2.5 times that of pristine SnTe. Such an extraordinary PF is attributed to the synergy of resonant levels and Sn vacancy suppression. Specifically, the Seebeck coefficient increases dramatically, reaching 88µVK-1 at room temperature. Meanwhile, by Sn vacancy suppression, carrier concentration, and mobility are optimized to ≈1019cm-3 and 740cm2V-1s-1, respectively. With the tourmaline compositing, Sn vacancies are further suppressed and the thermal conductivity simultaneously decreases, with the minimum lattice thermal conductivity of 0.9W m-1 K-1. Finally, the zT value ≈0.8 is obtained in the Sn0.99In0.01Te sample. The peak of the power output density reaches 0.89W cm-2 at a temperature difference of 600K. Such SnTe alloys with high and "temperature-independent" PF will offer an option for realizing high output power in thermoelectric devices.

High Quality Fe1+yTe Synthesized by Chemical Vapor Deposition with Conspicuous Vortex Flow

Abstract2D materials provide an ideal platform to explore novel superconducting behavior including Ising superconductivity, topological superconductivity and Majorana bound states in different 2D stoichiometric Ta‐, Nb‐, and Fe‐based crystals. However, tuning the element content in 2D compounds for regulating their superconductivity has not been realized. In this work, the synthesis of high quality Fe1+yTe with tunable Fe content by chemical vapor deposition (CVD) is reported. The quality and composition of Fe1+yTe are characterized by Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM). The superconducting behavior of Fe1+yTe crystals with varying Fe contents is observed. The superconducting transition of selected Fe1.13±0.06Te sample is sharp (ΔTc = 1 K), while Fe1.43±0.07Te with a high‐Fe content shows a relative broad superconducting transition (ΔTc = 2.6 K) at zero magnetic field. Significantly, the conspicuous vortex flow and a transition from a 3D vortex liquid state to a 2D vortex liquid state is observed in Fe1.43±0.07Te sample. This work highlights the tunability of the superconducting properties of Fe1+yTe and sheds light on the vortex dynamics in Fe‐based superconductors, which facilitates them to understand the intrinsic mechanisms of high‐temperature superconductivity.

Effective Nonstoichiometric Strategy Combined Post-annealing Process for Boosting Thermoelectric Properties in n-Type PbTe.

The intrinsic low electrical properties have hindered the enhancement of thermoelectric performance for n-type PbTe over a long period of time, primarily due to the generation of intrinsic Pb vacancies and other defects. In this work, PbTe samples with nonstoichiometric excess Pb atoms were successfully prepared by a melting reaction followed by spark plasma sintering. First, the introduction of precisely controlled excess Pb atoms has effectively eliminated the typical p-n transition phenomenon in PbTe systems by suppressing the generation of Pb vacancies. Further, the vacuum annealing process employed in nonstoichiometric samples increases the carrier mobility significantly because of the improved crystallinity and the lowered holes. Thus, the Hall mobility was optimized from 754.3 to 1215.9 cm2 V-1 s-1, while the power factor was ultimately elevated from 3087.8 to 4565.7 μW m-1 K-2 for the Pb1.03Te sample at 323 K. Benefited from the enhanced electrical transport properties near room temperature, an average zT ∼ 1.03 ranging from 323 to 723 K was achieved, demonstrating an outstanding performance in n-type nondoped PbTe. This work provides guidance for optimizing the thermoelectric performance of n-type PbTe and relevant telluride by reducing vacancies and other defects.

Constructing Coated Grain Nanocomposites and Intracrystalline Precipitates to Simultaneously Improve the Thermoelectric and Mechanical Properties of SnTe by MgB2 and Sb Co‐Doping

AbstractThermoelectric materials should be highly efficient and mechanically robust to satisfy the requirements of engineering applications. Herein, an integrated optimization strategy to improve both the thermoelectric performance and mechanical strength of SnTe is proposed. First, grain boundary engineering is applied to SnTe via MgB2 doping. The decomposition of MgB2 results in the Mg‐substituted SnTe solid solution and a special “core–shell” structure of Mg‐B compounds coated SnTe grain remarkably reducing the lattice thermal conductivity. Subsequently, trivalent Sb atoms are introduced to tune the carrier concentration and optimize the electrical performance of the MgB2‐doped sample. Sb‐rich Sn‐Te precipitates inside the grains further diminish the lattice's thermal conductivity. Consequently, a prominent improvement in average ZT of ≈117% is achieved for Sn0.78Sb0.16Te(MgB2)0.09 compared to pristine Sn1.03Te. Moreover, the compressive yield strength and Vickers hardness of Sn0.78Sb0.16Te(MgB2)0.09 are significantly increased by ≈168% and 176% relative to pristine Sn1.03Te, respectively. The quantitative strengthening models including grain boundary, dislocation, solid solution, intergranular, and precipitation strengthening in MgB2‐ and MgB2‐Sb‐doped Sn1.03Te samples are proposed, showing that the dominant strengthening mechanism is precipitation strengthening. This work provides an avenue for designing efficient and robust thermoelectric materials toward commercial application.

Preparation of High-Performance Mn-Doped SnTe Materials at High Pressure and High Temperature.

SnTe is an environmentally friendly medium-temperature thermoelectric material, but its inherent low power factor (PF) and high lattice thermal conductivity severely limit its application. In this study, based on the fact that Mn doping can induce band convergence, the high-pressure and high-temperature (HPHT) synthesis method was used to optimize the sample preparation and shorten the synthesis cycle to 30 min. The results show that the Sn0.93Mn0.10Te sample achieves the maximum PF value of 34.00 μW cm-1 K-2 at 775 K and PFave value of 21.36 μW cm-1 K-2 between 300-875 K. Microstructure analysis shows that the high-pressure synthesis method introduces abundant grain boundaries, various grain sizes, multiple defects, and pore structures into the sample. These microscopic crystal structures can effectively scatter phonons and lower the lattice thermal conductivity. The modification of these micromorphologies results in the Sn0.92Mn0.11Te sample attaining a minimum lattice thermal conductivity of 0.45 W m-1 K-1 at 625 K. The thermoelectric figure of merit (zT) of sample Sn0.92Mn0.11Te reaches a maximum value of 1.1 at 775 K, and the zTave reaches 0.63 in the range of 300-875 K. This study indicates that the synergistic effect of Mn element doping and microstructure modification can effectively optimize the thermoelectric transport performance of SnTe materials.

Realizing High Thermoelectric Performance in GeTe‐Based Supersaturated Solid Solutions

AbstractAs a highly promising thermoelectric material in the mid‐temperature region, pristine GeTe shows deteriorated thermoelectric properties due to the low Seebeck coefficient and the intrinsic high thermal conductivity. Herein, it is discovered that the introduction of strongly correlated d, f electrons by alloying rare‐earth atoms at Ge sites will increase the band effective mass and promote band convergency, which can largely improve the electric transport property. Moreover, the heavy atoms (Pb, Bi) doping induces optical phonon softening and the avoided crossing between acoustic and optical phonon branches, decelerating both optical and acoustic phonon velocities. The modulated composition wave from the fluctuated multi‐component distribution introduces a complicated hierarchical structure including point defects and nanoprecipitates, which provides all‐scale scattering sources for heat‐carrying phonons and results in low lattice thermal conductivity. Consequently, a high zT of 2.4 at 800 K can be obtained in the Ge0.86Pb0.09Bi0.03Ce0.005Te sample due to the combination of strong correlation for d, f electrons and the full‐spectrum scattering for phonons. This work provides an effective strategy to increase the thermoelectric performance of IV–VI compounds by combining the modulated band structure and the softening phonon dispersion.

PREPARATION AND THERMOELECTRIC PROPERTIES OF p-TYPE Ag(1-x)Cu(1+x)Te SAMPLES BY SPARK PLASMA SINTERING METHOD

The combination of silver (Ag), copper (Cu), and telluride (Te) yields silver copper telluride (AgCuTe), a new type of ternary liquid-like thermoelectric material. Due to its ultra-low lattice thermal conductivity and highly symmetrical cubic crystal structure, it exhibits excellent thermoelectric properties in the medium-to-high temperature range (400-600 K). However, hexagonal crystal structures with lower symmetry near room temperature can lead to higher thermal conductivity. In addition, the high carrier concentration of the hexagonal crystal structure results in a lower Seebeck coefficient for the material. This seriously affects the application of AgCuTe-based thermoelectric materials in the room temperature range. Therefore, how to improve the thermoelectric performance of AgCuTe-based thermoelectric materials in the room temperature range has received widespread attention from researchers. AgCuTe-based thermoelectric materials were successfully prepared by mechanically alloying Ag, Cu, and Te powders using a planetary ball mill combined with spark plasma sintering. On this basis, the thermoelectric properties of AgCuTe-based materials were optimized by adjusting the Ag/Cu ratio and Ag<sub>2</sub>Te/CuTe content. The results indicated that at 600 K, the Ag<sub>0.93</sub>Cu<sub>1.07</sub>Te sample obtained a high Seebeck coefficient value of approximately 171 μV/K<sup>-1</sup>. Finally, the ZT peak obtained from the Ag<sub>093</sub>Cu<sub>1.07</sub>Te sample was 1.06; compared with AgCuTe (ZT = 0.78), it had increased by about 36%.

BCG vaccination: issues of fuzzy logic in assessing its effectiveness

Background. Vaccination, as a method of specific prevention, is more than 100 years old. Over the years, there have been significant changes in living standards, children’s health, and immunology. The issues of the effectiveness of vaccination, the effectiveness of chemotherapy, and the need for revaccination are relevant in modern conditions. Aim. To evaluate long-term BCG vaccination data among the medical university students with assessment of the effectiveness of vaccination, and MBT infection during 20 years of follow-up. Materials and methods. 274 students of the medical university took part in the study, medical records were used (form No. 112/y). Records of BCG vaccination and Mantoux test results by year in mm. Results. In the long-term assessment of the phthisiological status of the students with 100% BCG vaccination in childhood, it was recognized as effective in 63.1%, ineffective in 18.3%. In 18.6%, the results did not meet the accepted standards. When evaluating the Mantoux 2 TE sample, MBT infection did not differ in the number and size of papules in all groups. Some students remained sensitive to tuberculin in the presence of a positive Diaskintest, in the absence of data for tuberculosis. Conclusion. Not all common concepts about the criteria for the effectiveness of vaccination fit into the existing rules, some aspects relate to the concept of fuzzy logic. Long-term observations using new methods of immunodiagnostics will allow to solve the issues at a new evidentiary level.

Temporal and Spectral Models as Correlates to Auditory-Perceptual Judgments of Overall Severity and Listener Comfort in Tracheoesophageal Voice.

This study pursued two objectives: (1) to determine the potential association between listener (n = 51) judgments of 20 male tracheoesophageal speaker samples for two auditory-perceptual dimensions of voice, overall severity (OS) and listener comfort (LC); and (2) to assess the temporal and spectral acoustic correlates for these auditory-perceptual dimensions. Three separate correlation analyses were performed to evaluate the association between OS and LC. First, scores of OS and LC from all listeners were pooled together, and then the correlation between OS and LC was computed. Second, scores of OS and LC were averaged over all listeners to derive a single estimate of OS and LC for each TE speaker sample; the correlation between the average OS and LC was then computed. Third, listener-to-listener variability in the association between OS and LC was evaluated by computing the correlation between OS and LC scores from each listener across all TE samples. Finally, two stepwise multiple regression models were created to relate the average LC score to spectral and temporal variation in the acoustic signal. While the pooled OS and LC scores had a moderate positive correlation (r = 0.66, p < 0.00001), the averaged OS and LC exhibited a near perfect positive correlation (r = 0.99, p < 0.00001). The significant differences between the pooled and averaged scores were explained by significant listener-to-listener variability in the association between OS and LC. OS and LC scores from 5 listeners had non-significant correlations, 10 had moderate correlations (r < 0.7), 35 listeners had high correlations (0.7 < r < 0.9), and 1 listener had a very high correlation (r < 0.9 < 1). Finally, the acoustic models created based on the spectral and temporal variations in the signal were able to account for 87.7% and 61.8% of variation in the average LC score. The strong correlations between OS and LC suggest that LC may, in fact, provide a more comprehensive auditory-perceptual surrogate for the voice quality of TE speakers. Although OS and LC are distinct conceptual dimensions, LC appears to have the advantage of assessing the social impact and potential communication disability that may exist in interactions between TE speakers and listeners.

Dilute Sc/Y doping in SnTe for efficient charge transport modulation and high thermoelectric performance

As a highly potential environmental-friendly medium-temperature thermoelectric material, pure SnTe exhibits relatively poor performance due to its intrinsic high carrier concentration and large energy offset between the two valence bands. In the present work, dilute Sc/Y doping is innovatively adopted to synergistically decrease carrier concentration and achieve strong band convergence. The Hall measurement results indicate that 3 % Y doping realizes the lowest carrier concentration of 2.6 × 1019 cm−3 in SnTe. Sc and Y have similar effects in promoting band convergence, with their effects second only to toxic Hg elements at the same doping concentration. The effective decoupling of electrical and thermal transport parameters results in a high average ZT of 0.453 for Sn0.975Sc0.025Te sample, which is 103 % higher than that of pure SnTe. In addition, with Li2Te alloying to regulate carrier concentration, high-performance temperature range could be adjusted, which is more conducive to dealing with different temperature scenarios. The role of Sc/Y doping disclosed in this work provides more options for further improving the performance of SnTe-based materials.

Global Islamic Banking Development: A Review and Bibliometric Analysis Using R-Biblioshiny Application

Islamic banking refers to a banking system that operates based on the principles of Islamic law and Sharia. The bank is guided by Islamic economics and follows specific guidelines and principles that differentiate it from the conventional banking system. The aim of this article is to provide insight into the extensive bibliometric literature on Islamic banking globally. The method used in this study is a bibliometric analysis of the literature collected in 2014 to 2023 from Scopus database,te sample of the study is 69 of the 317 publications. This research classifies and visualizes them using R-Biblioshiny software. Overall, this review provides an appropriate reference point for further research on 'Islamic Banking Globally'. The results of the bibliometric analysis reveal that the research focuses mainly on ”Islamic” and “Bank”. The findings of this research show that Islamic banking globally has experienced a significant trend in the last 9 years and to be of significant interest for discussion and research. Notably, the density visualization analysis, which involves measuring the co-occurrence network of keyword pairs reveals a compelling trend, thus indicating that this research theme is still interesting to research today. However, further research is needed in more detail considering the increasing development of Islam.

Corrosion property of Alloy 625 in Molten FLiNaK salt according to the Tellurium Concentrations

The corrosion properties of Alloy 625 have been studied in molten FLiNaK salt for 48 h at 700 °C as a function of tellurium (Te) concentrations using immersion tests and electrochemical methods. Under specific Te concentrations, we found that Te-induced corrosion can be suppressed and help protect the alloy against corrosion. The sample after the immersion test containing 0.1 wt.% Te (0.1 wt.% Te sample) had the lowest corrosion depth and mass loss, coupled with the highest charge transfer resistance, obtained using electrochemical impedance spectroscopy (EIS). On the other hand, the alloy with Te content above 0.1 wt.% exhibited severe corrosion penetration and lower charge transfer resistance in FLiNaK. Based on thermodynamical and electrochemical analyses, a corrosion mechanism of Alloy 625 in the molten salt containing Te was theorized involving the formation of stable corrosion products such as Ni/Fe rich layer depleted in Cr, nickel telluride, and chromium oxide.

First-principles calculations to investigate probing the influence of Mn and Mg doping concentration on electronic structures and transport properties of SnTe alloys

In this paper, the defect formation energies, the nature of chemical bonding, and electronic structures of Mn- and Mg-doped SnTe alloys were determined by first-principles calculations. The effects of substitutional atoms on thermoelectric parameters are analyzed by solving the Boltzmann equation. The solution solubility of Mg in SnTe alloy is higher than that of Mn, and the lattice distortion caused by Mn substituting Sn sites is more severe. In addition, the resonant level of Sn1-xMnxTe alloys possesses a flat trend of the valance band maximum, which improves the effective carrier mass and Seebeck coefficient. The Mg-doped alloys exhibit higher carrier mobility and electrical conductivity. The maximum value of the power factor is 5.78 mWm−1K−2 for the Sn0.97Mn0.03Te alloy. Corresponding directionally-solidified samples with the same composition were also prepared. The Sn0.97Mn0.03Te sample also achieves the highest ZT value of 1.28. These results provide theoretical reference for optimizing the thermoelectric performance of SnTe alloys by substituting atoms.

Lead Vacancy Promotes Sodium Solubility to Achieve Ultra-High zT in Only Ternary Pb1- x Nax Te.

Chemical doping of sodium is an indispensable means to optimize thermoelectric properties of PbTe materials, while a bottleneck is that an aliovalent atom doping leads to spontaneous intrinsic defects in the PbTe matrix, resulting in low dopant solubility. Therefore, it is urgent to improve the doping efficiency of Na for maximizing optimization. Here, an amazing new insight that the intentionally introduced Pb vacancies can promote Na solubility in ternary Pb1- x Nax Te is reported. Experimental analysis and theoretical calculations provide new insights into the inherent mechanism of the enhancement of Na solubility. The Pb vacancies and the resultant more dissolved Na not only synergistically optimize the carrier concentration and further facilitate the band convergence, but also induce a large number of dense dislocations in the grains. Consequently, benefiting from the self-enhancement of Seebeck coefficient and the minimization of lattice thermal conductivity, an 18% growth is obtained for the figure of meritzTin vacancy-containing Pb0.95 Na0.04 Te sample, reaching maximumzTmax ≈ 2.0 at 823 K, which achieves an ultra-high performance in only Na-doped ternary Pb1- x Nax Te materials. The strategy utilized here provides a novel route to optimize PbTe materials and represents an important step forward in manipulating thermoelectrics to improve dopant solubility.

High-performance Fe(Se,Te) films on chemical CeO2-based buffer layers

The fabrication of a Fe-based coated conductor (CC) becomes possible when Fe(Se,Te) is grown as an epitaxial film on a metallic oriented substrate. Thanks to the material’s low structural anisotropy, less strict requirements on the template microstructure allow for the design of a simplified CC architecture with respect to the REBCO multi-layered layout. This design, though, still requires a buffer layer to promote the oriented growth of the superconducting film and avoid diffusion from the metallic template. In this work, Fe(Se,Te) films are grown on chemically-deposited, CeO2-based buffer layers via pulsed laser deposition, and excellent properties are obtained when a Fe(Se,Te) seed layer is used. Among all the employed characterization techniques, transmission electron microscopy proved essential to determine the actual effect of the seed layer on the final film properties. Also, systematic investigation of the full current transport properties J(θ, H, T) is carried out: Fe(Se,Te) samples are obtained with sharp superconducting transitions around 16 K and critical current densities exceeding 1 MA cm−2 at 4.2 K in self-field. The in-field and angular behavior of the sample are in line with data from the literature. These results are the demonstration of the feasibility of a Fe-based CC, with all the relative advantages concerning process simplification and cost reduction.

High thermoelectric performance in entropy-driven Ge1−2x−yPbxSnxSbyTe

An ultrahigh zT of 2.5 at 723 K is achieved in an entropy driven Ge0.84Pb0.025Sn0.025Sb0.11Te sample showing a promising output power density (PDmax) of ∼590 mW cm−2 at ΔT = 448 K in a fabricated double leg device.