Diamond-like Structure Research Articles

Application of Materials Genome Methods in Thermoelectrics

Materials genome methods have played an essential role in accelerating the discovery of high-performance novel materials, and include high-throughput calculation, database construction, and machine learning. Over the past decades, these approaches have been increasingly used in lithium battery materials, solar cells, transparent conductors, and thermoelectrics. Thermoelectrics are functional materials that can directly convert electricity into heat and vice versa, offering new ideas for conventional power generation and refrigeration. The application of high-throughput methods can achieve more efficient screening of new thermoelectric materials and accelerate experimental development. This review summarizes the recent progress in the application of materials genome methods for different thermoelectric materials, such as half-Heuslers, diamond-like structures, oxides, and other materials. Finally, current advances in machine learning for thermoelectrics are discussed. The progress of the theoretical design of thermoelectrics has driven the development of high-performance thermoelectrics.

TRIANGULATION OF THE Cu-Sn-Se SYSTEM

Copper-containing compounds exhibit a wide range of properties, including thermoelectric, photoelectric, optical magnetic, superionic, superconducting, etc., which determines the areas of their practical use. In recent years, studies of complex copper selenides as promising thermoelectric (TE) materials have been actively carried out due to their advantages over traditional TE materials. Like binary Cu2Se, ternary selenides have low phonon thermal conductivity and high electrical conductivity and thermoelectric quality factor. Typically, copper-containing compounds belong to the p-type conductors and crystallize in four main structural types, among which phases with a diamond-like structure should be distinguished. Data on the nature of physicochemical interaction in the Cu – Sn – Se system are limited and contradictory. In view of this, it is important to carry out the triangulation of the ternary system Cu–Sn–Se, which is the first stage of the study of multicomponent systems.
 The investigated alloys of the Cu – Sn – Se system were obtained by fusing elementary components of high purity in vacuum quartz ampoules. The obtained alloys were investigated using X-ray powder diffraction (XRD) and differential thermal (DTA) analyzes. At the temperature of homogenizing annealing (170 ° С) there are seven binary Cu2Se, CuSe, CuSe2, Cu6Sn5, Cu3Sn, SnSe, SnSe2 and one ternary phase Cu2SnSe3 stable in the Cu – Sn – Se ternary system. The existence of the ternary phase of Cu2SnSe4 has not been confirmed, because the alloy corresponding to its stoichiometric composition is a mixture of Cu2SnSe3 and Se. To establish quasibinary sections of the Cu – Sn – Se system were performed the synthesis and phase analysis of only the significant points in the most informative areas. This ensures the establishment of the nature of the maximum number of quasibinary sections with a minimum number of syntheses. According to the results of phase analysis in combination with the literature data the triangulation of the Cu – Sn – Se system was carried out at 170 ° С. The quasibinarity of the Cu2Se – SnSe, Cu2Se – SnSe2, Cu2SnSe3 – Se, Cu2SnSe3 – SnSe, Cu6Sn5 – SnSe, Cu3Sn – SnSe, and Cu3Sn – Cu2Se sections was confirmed, and the quasibinarity of the Cu3Sn – Cu2Se was established at first.
 Keywords: triangulation; quasibinary section; phase analysis.

Temperature Dependence of Interfacial Bonding and Configuration Transition in Graphene/Hexagonal Boron Nitride Containing Grain Boundaries and Functional Groups.

The quasi-three-dimensional effect induced by functional groups (FGo) and the in-plane stress and structural deformation induced by grain boundaries (GBs) may produce more novel physical effects. These physical effects are particularly significant in high-temperature environments and are different from the behavior in bulk materials, so its physical mechanism is worth exploring. Considering the external field (strain and temperature field), the internal field (FGo and GBs) and the effect of distance between FGs and GBs on the bonding energy, configuration transition, and stress distribution of graphene/h-BN with FGo and GBs (GrO-BN-GBs) in the interface region were studied by molecular dynamics (MD). The results show that the regions linked by hydroxyl + epoxy groups gradually change from honeycomb to diamond-like structures as a result of a hybridization transition from sp2 to sp3. The built-in distortion stress field generated by the coupling effect of temperature and tension loading induces the local geometric buckling of two-dimensional materials, according the von Mises stresses and deflection theory. In addition, the internal (FGo and GBs) and external field (strain and temperature field) have a negative chain reaction on the mechanical properties of GrO-BN-GBs, and the negative chain reaction increases gradually with the increase in the distance between FGo and GBs. These physical effects are particularly obvious in high-temperature environments, and the behavior of physical effects in two-dimensional materials is different from that in bulk materials, so its physical mechanism is worth exploring.

Targeted synthesis of a high-stability cationic porous aromatic framework for highly efficient remediation of 99TcO4−

Efficient removal of 99TcO4− from nuclear wastewater is of great significance for the safe development of nuclear energy. In this work, a viologen-based cationic porous aromatic framework (TZ-PAF) was prepared as a novel sorbent for TcO4−. With 4,4′-bipyridine as the linker units, tetraphenylmethane was selected as the knot units to construct the diamond-like topology structure of TZ-PAF, which was benefit to its outstanding structural stability (thermal stability and acid resistance). The batch sorption experiments showed that TZ-PAF possessed fast sorption kinetics, higher sorption capacity (982 mg g−1 for ReO4−) and a highest removal depth (Kd for TcO4− was 5.02 × 106 mL g−1), which could be attributed to the low-density skeleton of TZ-PAF resulting in the high density of sorption sites. XPS and SEM analyses revealed that the mechanism of TcO4−/ReO4− capture was attributed to an anion-exchanged process in which Cl− of TZ-PAF was replaced by ReO4−. And more, the excellent reusability to capture ReO4− from a highly acidic solution (64.6%) and a simulated nuclear wastewater (77.6%) were obtained. In general, this work exhibited a new sorbent for the highly efficient and deep removal of TcO4− form nuclear wastewater, and would provide a valuable insight into designing novel high-stability sorbents for wastewater treatment.

Two Nonlinear Optical Thiophosphates Cu5Hg0.5P2S8 and AgHg3PS6 Activated by Their Tetrahedra-Stacking Architecture.

Infrared (IR) lasers are very critical in military and civil affairs, but it is also challenging and difficult to develop new infrared nonlinear optical (NLO) crystals. Herein, two new mixed-metal thiophosphates, Cu5Hg0.5P2S8 and AgHg3PS6 were discovered with the noncentrosymmetric (NCS) space group Pmn21 (No. 31) and Cc (No. 9). Cu5Hg0.5P2S8 displays a three-dimensional (3D) defective diamond-like structure stacked by ∞2[Cu2.5Hg0.25PS8]8- layers. AgHg3PS6 is characterized by a 3D framework consisting of distorted tetrahedrons. Moreover, the optical spectra show the band gaps of Cu5Hg0.5P2S8 and AgHg3PS6 are 2.12 and 1.85 eV, respectively, with a broad transparent range of 0.7-16.0 μm. In these two compounds, the dipole moments of nonlinear active units are strengthened due to the high-valence element P and the Hg-S bonds with large susceptibility. Therefore, AgHg3PS6 exhibits a moderate second harmonic generation (SHG) response that is half that of AgGaS2 (AGS) at 30-45 μm, while Cu5Hg0.5P2S8 performs a phase-matching (PM) behavior with a good SHG signal of 0.8 × AGS at 150-200 μm. The origin of NLO performance and electronic structures were revealed by the calculated dipole moments of distorted tetrahedra and theoretical calculations on the basis of density functional theory.

The formation of diamond-like carbon structure anchored in the nitrided layer of M50 steel during plasma-assisted thermochemical treatment

Diamond-like carbon (DLC) has excellent performance but cannot be directly applied in gears and bearings due to poor adhesion. A novel gradient composite layer that includes a hardened nitrided layer and a self-lubricating DLC structure at the outermost surface was fabricated on M50 steel via plasma-assisted thermochemical treatment. The structure evolution of the modified layer was comprehensively characterized by optical microscopy, scanning electron microscope (SEM), atomic force microscopy (AFM), transmission electron microscope (TEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The results show that the nanoparticles embedded in the DLC structure gradually increase until the nitrided diffusion layer. The DLC structure is like being anchored in the nitrided layer by nanoparticles carbide/nitride. The inner of the pre-nitrided layer is hardly affected during the plasma carburizing process. The gradient structure is verified to endow the treated samples with functionally graded hardness profile and super wear resistance by Vickers hardness tester, Nano-indentation tester, and pin-on-disk tribometer. The composite layer's tribological behavior was discussed through wear scar morphology observation by SEM and chemical structure in tracks with Raman spectroscopy. This method proposes a promising way for self-lubricating layer application in the steel matrix without complex operation and high economic cost.

Synthesis and Formation Condition of a New Cubic Carbon Nitride with Diamond-like Structure

Synthesis and Formation Condition of a New Cubic Carbon Nitride with Diamond-like Structure

Effect of network topology and crosslinker reactivity on microgel structure and ordering at liquid-liquid interface.

Polymer microgels synthesized in silico were studied at a liquid-liquid interface via mesoscopic computer simulations and compared to microgels with ideal (diamond-like) structure. The effect of crosslinkers reactivity ratio on the single particle morphology at the interface and monolayer behavior was examined. It was demonstrated that single particles deform into an explicit core-corona morphology when adsorbed at the interface. An increase in the crosslinker reactivity ratio decreased both the deformation ratio and the ratio between the core and corona sizes. Meanwhile, the compression of microgel monolayers revealed the existence of five distinct interparticle contact regimes, which have been observed experimentally in the literature. The crosslinker reactivity ratio appeared to define the compression range in these regimes and the sharpness of the transition between them. In particular, the higher the crosslinker reactivity ratio, the smaller the corona, and in turn, the narrower the range of the intermediate regime comprising both core-core and corona-corona contacts. The obtained results demonstrate that the more realistic model of microgels synthesized via precipitation polymerization allows for a more accurate prediction of the properties of the microgels at a liquid-liquid interface in comparison to the conventional diamond-like lattice model.

Self-Limiting Synthesis of Ultrathin Ge(110) Single Crystal via Liquid Metal.

Germanium, the prime applied semiconductor, is widely used in solid-state electronics and photoelectronics. Unfortunately, since the 3D diamond-like structure with strong covalent bonds impedes the 2D anisotropic growth, only the examples of ultrathin Ge along the (111) plane have been investigated, much less to the controllable synthesis along another crystal surface. Meanwhile, Ge(111) flakes are limited in semiconductor applications because of their gapless property. Here, ultrathin Ge(110) single crystal is synthesized with semiconductive property via gallium-associated self-limiting growth. The obtained ultrathin Ge(110) single crystal exhibits anisotropic honeycomb structure, uniformly incremental lattice, wide tunable direct-bandgap, blue-shifted photoluminescence emission, and unique phonon modes, which are consistent with the previous theoretical predictions. It also confirms excellent second harmonic generation and high hole mobility of 724 cm2 V-1 s-1 . The realization of ultrathin Ge(110) single crystal will provide an excellent candidate for application in electronics and optoelectronics.

Microstructure and biocompatibility of porous-Ta/Ti-6Al-4 V component produced by laser powder bed fusion for orthopedic implants

Tantalum is attracting more attention as an outstanding orthopedic implant material due to its excellent corrosion resistance and biocompatibility. However, the high melting point and strong oxygen affinity of tantalum make its preparation more difficult and costly. In addition, the high cost of raw materials also limits the wider application of tantalum. To break these limitations, porous tantalum coatings with different pore sizes were successfully prepared on Ti-6Al-4 V base by Laser Powder Bed Fusion, constructing an integral porous-Ta/Ti-6Al-4 V component with excellent bioactivity and osteointegration capacity. A strong metallurgical bonding was formed between tantalum and Ti-6Al-4V, and the bonding strength is more than 460 MPa. The porous tantalum coating is designed as diamond-like structure with strong symmetry. The porosity of tantalum coatings is 70%, and the pore size ranges from 447 to 865 μm. Its deformation characteristics are extremely similar to those of natural cancellous bone. The average compressive yield strength of the porous Ta coatings ranges from 5.8 to 24. 2 MPa. And the average compressive elastic modulus of porous Ta coatings (0.6–1.5 GPa) was close to that of cancellous bone. Corrosion resistance tests proved that the Ta-coated Ti-6Al-4 V alloy had an excellent chemical stability in simulated body fluid. In vitro tests showed that Mouse calvarial preosteoblasts presented a good adhesion and growth behavior on porous Ta coatings. Therefore, it is preliminarily determined that the customized porous-Ta/Ti-6Al-4 V component by Laser powder bed fusion can be a candidate material for orthopedic implantation. • A novel high-interface-strength porous Ta/Ti6Al4V component was successfully manufactured using Laser Powder Bed Fusion. • The mechanical properties of the component met the requirements of ideal orthopedic implant materials. • The component had a good chemical stability and an excellent biocompatibility in simulated body fluid.

Simulation of magneto-mechanical response of ferrogel samples with various polymer structure

ABSTRACT Following the coarse-grained molecular dynamics approach, we propose a model of a small ferrogel sample (containing up to 1000 magnetic nanoparticles), in which the polymer matrix is presented in the form of a quasi-regular mesh of spring-beads chains and the filler particles are located at the mesh nodes. The state of the sample in the absence of an external field and in the process of quasi-static magnetization is considered for two types of mesh topology (simple cubic and diamond-like), different values of the filler concentration, the strength of dipole interaction, and the energy of magnetic anisotropy. Simulation shows that the use of a softer matrix with a diamond-like structure increases the magneto-mechanical response of the ferrogel. The presence of magnetic anisotropy leads to effective hardening of the ferrogel and, thus, prevents particle clustering and sample magnetization. It was also found that the anisotropy energy determines the type of field-induced changes in the sample volume – this aspect of material behavior is important for the use of ferrogels in controlled delivery and/or release of drugs.

Tribological properties of carbon-containing composite materials prepared by high-pressure high-temperature synthesis

The composite materials (CM) based on Co, Ti-Cu, and Pt and reinforced with diamond-like carbon particles and diamonds with different component ratios have been obtained by high-pressure high-temperature synthesis (5–9 GPa, 800–1800 °C). The methods of optical microscopy, dynamic indentation, and tribological tests were used to establish the correlation between the structure and properties of the reinforcing phase and CM and to define the limits of the applicability of the CM as tribotechnical materials. Low friction coefficients (0.08–0.06) were demonstrated by the CM reinforced with a superhard (35–40 GPa) diamond-like phase obtained from ball-milled fullerites with a cobalt binder as well as by the CM with diamonds regardless of the binder type and particle size. The wear resistance of the cobalt-based CM increases with increasing hardness of the reinforcing diamond-like particles. The condition for obtaining super wear-resistant CM from metal-fullerene mixtures is the synthesis at a temperature of about 800 °C, which ensures the collapse of fullerene molecules, but limits the graphitization of the diamond-like structure.

Colloidal synthesis of diamond-like compound Cu2SnTe3 and thermoelectric properties of (Cu0.96InTe2)1−(Cu2SnTe3) solid solutions

Cu based ternary compounds with diamond-like crystal structure received intensive attentions in last decade as potential thermoelectric materials whereas the investigation of high order derivatives (e. g. I2-IV-VI3) with anion as Te is lacking due to the synthesis difficulty in conventional solid state reaction. Herein, Cu2SnTe3 has been synthesized by colloid method and its high temperature thermoelectric properties have been preliminarily explored. The electrical conductivity of pristine Cu2SnTe3 has been found as high as ~105 S m−1 owning to intrinsically high carrier concentration, which resulted in low thermoelectric performance. Thus, the pristine Cu2SnTe3 compound has been used as solid solution component to alloy with CuInTe2, which also possesses diamond-like structure but with low carrier density. The results have shown that the thermoelectric performance of CuInTe2 can be enhanced through alloying with Cu2SnTe3, primarily resulting from huge reduction in lattice thermal conductivity. The sample with nominal composition of (Cu0.96InTe2)0.97(Cu2SnTe3)0.03 has reached a maximum zT value of ~0.9 at 823 K. Our findings should shed light on design of new thermoelectric compounds in diamond-like semiconductor family.

Methodology and results of studying the states of hydrogen in graphene structures

In this work, an effective methodology of analysis of thermal desorption spectra (TDS) of hydrogen in carbon materials was further developed and applied. The methodology makes it possible, from TDS data of one heating rate, to determine the activation energies and pre-exponential factors of the rate constants of desorption processes. The TDS data of Rajasekaran et al. for hydrogenated epitaxial graphenes with a diamond-like structure (as in graphane) were analyzed. Some new information was obtained about the states of hydrogen in such unusual structures. It was shown that about half of the hydrogen contained in the samples is localized in the interfacial regions (between graphene and the substrate), while the desorption of such hydrogen is limited by diffusion (with three activation energies (34 kJ/mol(H2), 45 kJ/mol(H2), and 68 kJ/mol(H2)) of hydrogen molecules in these regions to the lateral surfaces of the samples. It was also shown that the rest of the hydrogen is localized on the top surface of the samples, while desorption of hydrogen atoms occurs with two activation energies and frequency factors (174 kJ/mol(H), 2 × 1013 s−1, and 256 kJ/mol(H), 3 × 1018 s−1); the obtained quantities are comparable to the related characteristics for graphane.

Inside Back Cover: Li4MgGe2S7: The First Alkali and Alkaline‐Earth Diamond‐Like Infrared Nonlinear Optical Material with Exceptional Large Band Gap (Angew. Chem. Int. Ed. 45/2021)

Combining alkali and alkaline-earth metal tetrahedra units with an excellent diamond-like structure (DLS) template, the first alkali and alkaline-earth metal DLS infrared nonlinear optical (NLO) material Li4MgGe2S7 was rationally designed and fabricated. This work enriches the diversity of DLS compounds, and opens an avenue for the design and exploration of new infrared NLO materials with excellent NLO properties, as outlined by Shilie Pan, Junjie Li et al. in their Research Article on page 24333.

Effects of Substrate Bias Voltage on Structure of Diamond-Like Carbon Films on AISI 316L Stainless Steel: A Molecular Dynamics Simulation Study.

With the recent significant advances in micro- and nanoscale fabrication techniques, deposition of diamond-like carbon films on stainless steel substrates has been experimentally achieved. However, the underlying mechanism for the formation of film microstructures has remained elusive. In this study, the growth processes of diamond-like carbon films on AISI 316L substrate are studied via the molecular dynamics method. Effects of substrate bias voltage on the structure properties and sp3 hybridization ratio are investigated. A diamond-like carbon film with a compact structure and smooth surface is obtained at 120 V bias voltage. Looser structures with high surface roughness are observed in films deposited under bias voltages of 0 V or 300 V. In addition, sp3 fraction increases with increasing substrate bias voltage from 0 V to 120 V, while an opposite trend is obtained when the bias voltage is further increased from 120 V to 300 V. The highest magnitude of sp3 fraction was about 48.5% at 120 V bias voltage. The dependence of sp3 fraction in carbon films on the substrate bias voltage achieves a high consistency within the experiment results. The mechanism for the dependence of diamond-like carbon structures on the substrate bias voltage is discussed as well.

THE QUATERNARY CHALCOGENIDE COMPOUND Ag2FeGeSe4: A REVISION OF THEIR CRYSTAL STRUCTURE AND MAGNETIC PROPERTIES

Background: Quaternary compounds bellowing to the I2-II-IV-VI4 system are of considerable technological interest due to their possible use in the preparation of solar cell and thermoelectric materials devices. In recent years, considerable attention has been focused on the detailed study of quaternary chalcogenide compounds related to the chalcopyrite compounds, particularly AgInSe2, which has emerged as a leading material for the preparation of photovoltaic devices due to their potential applications in solar cell technology. Aims: This work focuses on synthesis, chemical analysis, thermal study, magnetism measurement, and crystal structural characterization of the quaternary semiconductor Ag2FeGeSe4, an essential member of the family I2-II-IV-VI4. Methods: This material was synthesized by the melt and anneal technique. The chemical analysis was carried out by scanning electron microscopy (SEM) and differential thermal analysis (DTA). Magnetic susceptibility () as a function of temperature and magnetization as a function of the magnetic field were also performed, and crystal structure analysis was made employing the Rietveld method with powder X-ray diffraction data. Results and Discussion: The preparation confirms the formation of the quaternary compound with stoichiometric 2:1:1:4 according to the chemical analysis. This quaternary compound melt at 1015 K, and show an antiferromagnetic behavior with Neel temperature TN of 240 K. The Debye temperature (D) estimated for this compound was 194 K. The quaternary chalcogenide compound Ag2FeGeSe4 crystallizes in the orthorhombic space group Pmn21, Z = 4, with unit cell parameters: a = 7.6478(1) Å, b = 6.5071(1) Å, c = 6.4260(1) Å, and V = 319.79(1) Å3, in a wurtzite-stannite arrangement with a Cu2CdGeS4-type structure, which is characterized by a three-dimensional arrangement of slightly distorted AgSe4, FeSe4, and GeSe4 tetrahedra connected by corners. In this structure, each Se atom is coordinated by four cations located at the corners of a slightly distorted tetrahedron, and each cation is tetrahedrally bonded to four anions. Conclusions: The melt and anneal method remains effective for preparing compounds chalcogenides as the quaternary Ag2FeGeSe4, a new member of I2-II-IV-VI4 family of semiconductors, which crystallizes in the non-centrosymmetric space group Pmn21 with diamond-like structure. The crystal structure information of this compound allows explaining their magnetic properties, which in combination with its semiconductor properties make this material a potential aspirant for different applications, mainly in solar cells.

Highly Distorted [HgS4] Motif-Driven Structural Symmetry Degradation and Strengthened Second-Harmonic Generation Response in the Defect Diamond-Like Chalcogenide Hg3P2S8

Chalcogenides with diamond-like (DL) structures are a treasury of infrared nonlinear optical (NLO) materials. Here, a ternary Hg-based chalcogenide with a defect DL structure, Hg3P2S8, is synthesized by solid-state reaction. Driven by the highly distorted [HgS4] tetrahedra, this compound displays an interesting structural symmetry degradation from tetragonal to orthorhombic compared with its analogue Zn3P2S8. Meanwhile, the overall performances of Hg3P2S8 are quite remarkable, including a very strong phase-matchable second-harmonic generation (SHG) response (4.2 × AgGaS2), large band gap (2.77 eV), wide IR transparent range (0.45-16.7 μm), and high laser-induced damage threshold (4 × AGS). Furthermore, the theoretical analysis and local dipole moment calculations elucidate that the highly distorted [HgS4] tetrahedra contribute a lot to the enhancement of the SHG effect. This discovery will motivate the exploration of other DL Hg-based chalcogenides serving as high-performing mid-IR NLO materials.

Assembly of Chiral Cluster-Based Metal-Organic Frameworks and the Chirality Memory Effect during their Disassembly.

Many metal clusters are intrinsically chiral but are often synthesized as a racemic mixture. By taking chiral Ag14(SPh(CF3)2)12(PPh3)4(DMF)4 (Ag14) clusters with bulky thiolate ligands as an example, we demonstrate herein an interesting assembly disassembly (ASDS) strategy to obtain the corresponding, optically pure crystals of both homochiral enantiomers, R-Ag14m and S-Ag14m. The ASDS strategy makes use of two bidentate linkers with different chiral configurations, namely, (1R,2R,N1E,N2E)-N1,N2-bis(pyridin-3-ylmethylene)cyclohexane-1,2-diamine (LR) and the corresponding chiral analogue LS. For comparison, we also use the racemic mixture of equimolar of LR and LS (LRS). Three three-dimensional (3D) Ag14-based metal-organic frameworks (MOFs) were characterized by X-ray crystallography to be [Ag14(SPh(CF3)2)12(PPh3)4(LR)2]n (Ag14-LR), [Ag14(SPh(CF3)2)12(PPh3)4(LS)2]n (Ag14-LS), and [Ag14(SPh(CF3)2)12(PPh3)4(LRS)2]n (Ag14-LRS), respectively. As expected, the building blocks in Ag14-LR or Ag14-LS are homochiral R-Ag14 or S-Ag14, respectively. In contrast, Ag14-LRS is achiral and crystallizes with a diamond-like structure containing alternate R-Ag14 and S-Ag14 clusters. During the assembly process, the racemic Ag14 clusters were converted to homochiral building blocks, namely, R-Ag14 for Ag14-LR and S-Ag14 for Ag14-LS. Subsequently, the chiral linkers were removed from the crystals of Ag14-LR and Ag14-LS via hydrolysis with water, and from the disassembled solid material Ag14-DR and Ag14-DS, optically pure enantiomers R-Ag14m and S-Ag14m were obtained. It is hoped that this simple assembly strategy can be used to construct cluster-based chiral assemblage materials and that the subsequent disassembly protocol can be used to obtain optically pure chiral cluster molecules from as-prepared racemic mixtures.

Grain size-induced enhancement of thermoelectric performance of Cu3Sb1−xInxSe4 materials

The ternary Cu3SbSe4 thermoelectric material with diamond-like structure exhibits good thermoelectric performance in the middle temperature region. In this study, the Cu3Sb[Formula: see text]In[Formula: see text]Se4 ([Formula: see text]= 0–0.03) materials were fabricated by melting-annealing-ball milling-hot pressing process. The influences of In-doping and grain size on the microstructure and thermoelectric properties of Cu3Sb[Formula: see text]In[Formula: see text]Se4 were evaluated. It is found that the electricity conduction at room temperature for Cu3Sb[Formula: see text]In[Formula: see text]Se4 sample was significantly increased to 6.1 × 103Sm[Formula: see text] due to the In-doping. Additionally, during the powder processing, a relatively low thermal conductivity for the refinement Cu3Sb[Formula: see text]In[Formula: see text]Se4-BM-72H sample was obtained. Benefiting from the enhanced electrical conductivity and the decreased thermal conductivity, the maximum zT value of 0.75 was achieved for Cu3Sb[Formula: see text]In[Formula: see text]Se4-BM-36H at 650 K.