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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Copper nanoparticle structures for reduction of carbon dioxide to multicarbon products

This disclosure provides systems, methods, and apparatus related to copper nanoparticle structures for reduction of carbon dioxide to multicarbon products. In one aspect, a method includes providing a plurality of copper nanoparticles. The plurality of copper nanoparticles are deposited on a support. The plurality of copper nanoparticles are transformed to a plurality of copper structures during an operation in which carbon dioxide is reduced. The plurality of copper nanoparticles on the support are used as a working electrode in an electrochemical cell during the operation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Temperature-dependent polymorphism and magnetic properties of three-dimensional copper pyromellitate coordination polymers containing 4,4′-dipyridylamine

A pair of three-dimensional divalent copper pyromellitate (1,2,4,5-benzene-tetracarboxylate, pyro) coordination polymers containing 4,4′-dipyridylamine (dpa) was hydrothermally prepared and structurally characterized by single-crystal X-ray diffraction. The higher-temperature phase ([H{sub 2}dpa][Cu{sub 3}(pyro){sub 2}(H{sub 2}O){sub 3}]·2.5H{sub 2}O){sub n} (1) displays an acentric 3-D 4,4,6-connected anionic network with (4{sup 4}5.6)(5{sup 4}8{sup 2})(4{sup 4}5{sup 4}6{sup 3}7{sup 4}) topology, featuring (Cu{sub 2}(OCO){sub 4}) paddlewheel dimers and isolated copper ions. Charge-balancing H{sub 2}dpa cations are embedded in incipient voids. Prepared at lower temperature, ([Cu{sub 3}(pyro){sub 2}(dpa){sub 2}(dpaH){sub 2}]·3H{sub 2}O){sub n} (2) manifests a 3-D 4,4,4-connected neutral network with uncommon (4{sup 2}6{sup 4}){sub 4}(6{sup 4}8{sup 2}) frl topology based on (Cu{sub 3}(OCO){sub 2}) linear trimers. Antiferromagnetic coupling (J=–82(5) cm{sup –1}) was observed within the (Cu{sub 2}(OCO){sub 4}) dimeric units in 1, while weak ferromagnetic coupling (J=1.0(4) cm{sup –1}) was evident for the (Cu{sub 3}(OCO){sub 2}) linear trimers in 2. Thermal degradation behavior of these new materials is also presented. - Graphical abstract: Two copper pyromellitate coordination polymers containing 4,4′-dipyridylamine were prepared. The higher-temperature phase ([H{sub 2}dpa][Cu{sub 3}(pyro){sub 2}(H{sub 2}O){sub 3}]∙2.5H{sub 2}O){sub n} displays an acentric 3-D trinodal anionic network with (4{sup 4}5.6)(5{sup 4}8{sup 2})(4{sup 4}5{sup 4}6{sup 3}7{sup 4}) topology, featuring antiferromagnetically coupled (Cu{sub 2}(OCO){sub 4}) paddlewheel dimers and isolated copper ions. - Highlights: • Copper pyromellitate (pyro) coordination polymers with 4,4′-dipyridylamine (dpa). • Higher-temperature phase 1 has 3-D anionic trinodal network with H{sub 2}dpa cations. • Lower-temperature phase 2 has rare 3-D frl network. • Dimers and chains in 1 show antiferromagnetism, trimers in 2 show ferromagnetism.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2013

Co-evaporation of transition metal salt and SiO powder toward copper(or nickel)/silicon-contained composite nanostructures

Graphical abstract: Copper(or nickel)/silicon-contained composite nanostructures were successfully synthesized by co-evaporating SiO powder and corresponding transition metal salts (nickel formate and copper sulfate). Display Omitted Highlights: ► Novel nanostructures were synthesized by co-evaporating SiO and metal salts. ► A pre-sintering process was used in the synthesis of copper/silicon nanocomposites. ► A Ni{sub 31}Si{sub 12}/Si/SiO{sub 2} nanocomposite was obtained. ► Peapod-like copper/silicon-contained nanocomposites were obtained. ► On the basis of experimental results, the formation mechanism was discussed. -- Abstract: We demonstrate that several novel copper(or nickel)/silicon-contained composite nanostructures were successfully synthesized by co-evaporating SiO powder and corresponding transition metal salts (transition metal organic salt and transition metal inorganic salt), including nickel formate, cobalt acetate, and copper sulfate. The morphologies, compositions, and crystal structures of products were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). The results indicate that the morphology and composition of formed copper(or nickel)/silicon-contained composite nanostructures are dramatically influenced by the distance between SiO powder and transition metal salts, or by the pre-sintering temperature of the reactants. The possible formation mechanisms of these composite nanostructures were discussed on the basis of experimental observations.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Distribution of copper, silver and gold during thermal treatment with brominated flame retardants

Highlights: • Copper, silver and gold during thermal treatment with brominated flame retardants. • Distribution of copper, silver and gold during thermal processing. • Thermodynamic considerations of the bromination reactions. - Abstract: The growing consumption of electric and electronic equipment results in creating an increasing amount of electronic waste. The most economically and environmentally advantageous methods for the treatment and recycling of waste electric and electronic equipment (WEEE) are the thermal techniques such as direct combustion, co-combustion with plastic wastes, pyrolysis and gasification. Nowadays, this kind of waste is mainly thermally treated in incinerators (e.g. rotary kilns) to decompose the plastics present, and to concentrate metals in bottom ash. The concentrated metals (e.g. copper, precious metals) can be supplied as a secondary raw material to metal smelters, while the pyrolysis of plastics allows the recovery of fuel gases, volatilising agents and, eventually, energy. Indeed, WEEE, such as a printed circuit boards (PCBs) usually contains brominated flame retardants (BFRs). From these materials, hydrobromic acid (HBr) is formed as a product of their thermal decomposition. In the present work, the bromination was studied of copper, silver and gold by HBr, originating from BFRs, such as Tetrabromobisphenol A (TBBPA) and Tetrabromobisphenol A-Tetrabromobisophenol A diglycidyl ether (TTDE) polymer; possible volatilization of the bromides formed was monitored using a thermo-gravimetric analyzer (TGA) and a laboratory-scale furnace for treating samples of metals and BFRs under an inert atmosphere and at a wide range of temperatures. The results obtained indicate that up to about 50% of copper and silver can evolve from sample residues in the form of volatile CuBr and AgBr above 600 and 1000 °C, respectively. The reactions occur in the molten resin phase simultaneously with the decomposition of the brominated resin. Gold is resistant to HBr and remains unchanged in the residue.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Optical properties of stabilized copper nanoparticles

Optical studies involving calculation of Band Gap of the synthesized copper nanoparticles were carried out in the wavelength range of 500 to 650 nm at room temperature, the particles showed high absorption at 550 nm indicating their good absorptive properties. In this method water is used as the medium for reduction of copper ions in to copper Nanoparticles the stabilization of copper Nanoparticles was studied with starch both as a reductant and stabilizer,. The reaction mixture was heated using a kitchen microwave for about 5 minutes to attain the required temp for the reaction. The pH of the solution was adjusted to alkaline using 5% solution of NaOH. Formation of Copper Nanoparticles was indicated by change in color of the solution from blue to yellowish black which is supported by the UV absorption at 570 nm.the synthesized particles were washed with water and alcohol. The optical properties depend upon absorption of radiations which in turn depends upon ratio of electrons and holes present in the material and also on the shape of the nanoparticles. In the present investigation it was observed that optical absorption increases with increase in particle size. The optical band gap for the Nanoparticles was obtained from plots between hv vs. (αhv){sup 2} and hv vs. (αhv){sup 1/2}. The value of Band gap came out to be around 1.98–2.02 eV which is in close agreement with the earlier reported values.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2016

X-ray natural circular dichroism in copper metaborate

The local electronic structure of copper ions in a copper metaborate CuB{sub 2}O{sub 4} crystal is studied on the ESRF synchrotron using X-ray absorption polarization-dependent spectroscopy. The X-ray natural circular dichroism near the K absorption edge of copper is measured in the direction that is perpendicular to crystal axis c. The data obtained indicate the presence of hybridized p–d electronic states of copper. Theoretical calculations are used to separate the contributions of the two crystallographically nonequivalent positions of copper atoms in the unit cell of CuB{sub 2}O{sub 4} to the absorption and X-ray circular dichroism spectra of the crystal.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Characteristics and Processing of Hydrogen-Treated Copper Powders for EB-PBF Additive Manufacturing

The fabrication of high purity copper using additive manufacturing has proven difficult because of oxidation of the powder feedstock. Here, we present work on the hydrogen heat treatment of copper powders for electron beam powder bed fusion (EB-PBF), in order to enable the fabrication of high purity copper components for applications such as accelerator components and vacuum electronic devices. Copper powder with varying initial oxygen contents were hydrogen heat-treated and characterized for their chemistry, morphology, and microstructure. Higher initial oxygen content powders were found to not only reduce surface oxides, but also reduce oxides along the grain boundaries and form trapped H 2 O vapor inside the particles. The trapped H 2 O vapor was verified by thermogravimetric analysis (TGA) and residual gas analysis (RGA) while melting. The mechanism of the H 2 O vapor escaping the particles was determined by in-situ SEM heated stage experiments, where the particles were observed to crack along the grain boundaries. To determine the effect of the EB-PBF processing on the H 2 O vapor, the thermal simulation and the validation of single melt track width wafers were conducted along with melting single layer discs for chemistry analysis. A high speed video of the EB-PBF melting was performed in order to determine the effect of the trapped H 2 O vapor on the melt pool. Finally, solid samples were fabricated from hydrogen-treated copper powder, where the final oxygen content measured ~50 wt. ppm, with a minimal residue hydrogen content, indicating the complete removal of trapped H 2 O vapor from the solid parts.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Crystalline phase transitions and water-soluble complexes of copper(Ⅰ) 2-hydroxyethanethiolate

We report the coordination polymer copper(I) 2-hydroxyethanethiolate, (CuSCH 2 CH 2 OH) n , though insoluble in all common solvents, dissolved readily in basic aqueous solutions of the thiolate anion (HOCH 2 CH 2 S – ) of 2-mercaptoethanol to form a single species: the tetranuclear cluster [Cu 4 (μ-SCH 2 CH 2 OH) 6 ] 2– . From this solution were grown X-ray quality single crystals of copper(I) 2-hydroxyethanethiolate. This compound underwent a hitherto unknown crystal phase transition at ca. 6 °C, from point group P2 1 2 1 2 1 to Pna2 1 , with noticeable changes in the geometry of the Cu-S layer and in the orientation of the alkylthiolate side chains. When the bulky base tetrabutylammonium hydroxide was employed in the aqueous thiolate solution used to dissolve (CuSCH 2 CH 2 OH) n , the water-soluble polynuclear copper(I) complex bis(tetrabutylammonium) hexakis(μ-2-hydroxyethanethiolato) tetracuprate(I), [(C 4 H 9 ) 4 N] 2 [Cu 4 (μ-SCH 2 CH 2 OH) 6 ], could be isolated as X-ray quality crystals. Structural characterization of this complex revealed a tetrahedral arrangement of copper(I) centers with thiolates bridging the edges of the tetrahedra. On standing, this complex degraded to a larger polynuclear Cu(I) sulfide cluster.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Significantly Promoting the Thermal Conductivity and Machinability of Negative Thermal Expansion Alloy via In Situ Precipitation of Copper Networks

Rapid advancements in electronic devices yield an urgent demand for high-performance electronic packaging materials with high thermal conductivity, low thermal expansion, and great mechanical properties. However, it is a great challenge for current design philosophies to fulfill all the requirements simultaneously. Here, an effective strategy is proposed for significantly promoting the thermal conductivity and machinability of negative thermal expansion alloy (Zr,Nb)Fe 2 through eutectic precipitation of copper networks. The eutectic dual-phase alloy exhibits an isotropic chips-matched thermal expansion coefficient and a thermal conductivity enhancement exceeding 200% compared with (Zr,Nb)Fe 2 , along with an ultimate compressive strength of 550 MPa. The addition of copper reorganizes the composition of (Zr,Nb)Fe 2 , which smooths the magnetic transition and shifts it toward higher temperature, resulting in linear low thermal expansion in a wide temperature range. The highly fine eutectic copper lamellae construct high thermal conductivity networks within (Zr,Nb)Fe 2 , serving as highways for heat transfer electrons and phonons. The in situ forming of eutectic copper lamellae also facilitates the mechanical properties by enhancing interfacial bonding and bearing additional stress after yielding of (Zr,Nb)Fe 2 . This work provides a novel strategy for promoting thermal conductivity and mechanical properties of negative thermal expansion alloys via eutectic precipitation of copper networks.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Early Stage Detection of Stress Due to Copper on Maize (Zea mays L.) by Laser-Induced Fluorescence and Infrared Spectroscopy

Laser-induced fluorescence (LIF) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy has been applied for the nondestructive, label free, and rapid analyses of the impact of copper (25, 50, and 75 μM) on maize seedlings at an early stage before the changes appear visually on the plant. The LIF measurement has been used to detect the signs of stress in the photosynthetic pigment. The integrated areal intensity and increasing fluorescence intensity ratios indicate decrease in the photosynthetic pigments in the leaves of maize plants stressed with copper. The ATR-FTIR technique has been utilized to estimate the changes arising in the cell wall polysaccharides, amino acid, secondary structure of protein and lipid content of the leaves of control and copper-treated maize seedlings. The second derivative and curve fitting analyses have been applied for the enhancement of the spectral variations and quantitative estimation of the changes arising in the biochemical profile. The result shows an increase in the pectin, lignin, amino acid, and protein content and reduction in the amount of cellulose and lipid in the leaves of maize seedlings due to the treatment of copper. This study indicates the toxic response of copper by hampering the growth and reduction in the photosynthetic pigments and biochemical content of the maize seedlings. This study also demonstrates the feasibility of the spectroscopic techniques (LIF and ATRFTIR) as a rapid, label free, and nondestructive probe for the assessment of stress and monitoring of crops.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Anti-Prostate Cancer Activity of 8-Hydroxyquinoline-2-Carboxaldehyde–Thiosemicarbazide Copper Complexes by Fluorescent Microscopic Imaging

Copper 8-hydroxyquinoline-2-carboxaldehyde–thiosemicarbazide (CuHQTS) and copper 8-hydroxyquinoline-2-carboxaldehyde–4,4-dimethyl-3-thiosemicarbazide (CuHQDMTS) are two copper thiosemicarbazone complexes with potent anticancer activity on cisplatin-resistant neuroblastoma cells. This study aimed to evaluate anti-prostate cancer activity of these two copper complexes in vitro. Both CuHQTS and CuHQDMTS inhibited proliferation of prostate cancer cells and showed cytotoxicity on prostate cancer cells carrying green fluorescent protein (GFP) by fluorescent microscopic imaging. The findings of this study demonstrated anti-prostate cancer activity of CuHQTS and CuHQDMTS and suggested that GFP-carrying prostate cancer cells might be used for testing anticancer activity of copper complexes by fluorescent microscopic imaging.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Surface Self-nanocrystallization in Copper Electroforming

The coarse columnar grain layer generated on top of electroforming deposits leads to low surface strength and poor global performance of deposits. Here, we introduce a particle abrasive-induced surface self-nanocrystallization process, which is a part of the electroforming process rather than involving complex poststeps using special equipment. It can generate a thickness-controllable surface nanocrystalline layer on top of copper deposits for performance enhancement. In this study, surface nanocrystalline layers of 10, 20, 50 and 120 μm were fabricated on top of 500-μm-thick copper deposits. The tensile strength of copper deposits increases from 234 to 246, 330, 383 and 421 MPa, with a corresponding decrease in elongation from 26 to 25, 24, 15 and 6%, respectively. The moderately thick surface nanocrystalline layer makes the copper deposits exhibit good comprehensive mechanical properties. In addition, the surface self-nanocrystallization also makes the copper deposits show a better corrosion resistance in a neutral aqueous 0.1 M NaCl solution. This study aims to promote a convenient, controllable and reliable surface self-nanocrystallization process in electroforming for improving the global performance of deposits.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Effect of MgCl{sub 2} on the Corrosion Behavior of Copper Under Periodic Wet/Dry Cycle Condition

The corrosion behaviors of copper under periodic wet/dry cycle conditions were investigated. The characteristics of the corrosion product formed on copper were analyzed by x-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and in situ electrochemical impedance spectroscopy. Weight loss results showed that the corrosion of copper under an MgCl{sub 2} deposition condition was more severe than that under NaCl. The main corrosion products formed on the tested sample under NaCl deposition condition consisted of Cu{sub 2}Cl(OH){sub 3} and Cu{sub 2}O, while those under the MgCl{sub 2} deposition condition consisted of Cu{sub 2}Cl(OH){sub 3} and Mg{sub 2}(OH){sub 3}Cl·4H{sub 2}O. In the case of the NaCl deposition condition, a two-layered structure formed during the corrosion process. However, the corrosion product layer formed on copper under the MgCl{sub 2} deposition condition had an extremely loose structure. The effect of MgCl{sub 2} on the corrosion mechanism of copper is discussed.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Laser-Assisted Reduction of Highly Conductive Circuits Based on Copper Nitrate for Flexible Printed Sensors

Stretchable electronic sensing devices are defining the path toward wearable electronics. High-performance flexible strain sensors attached on clothing or human skin are required for potential applications in the entertainment, health monitoring, and medical care sectors. In this work, conducting copper electrodes were fabricated on polydimethylsiloxane as sensitive stretchable microsensors by integrating laser direct writing and transfer printing approaches. The copper electrode was reduced from copper salt using laser writing rather than the general approach of printing with pre-synthesized copper or copper oxide nanoparticles. An electrical resistivity of 96 μΩ cm was achieved on 40-μm-thick Cu electrodes on flexible substrates. The motion sensing functionality successfully demonstrated a high sensitivity and mechanical robustness. Furthermore, this in situ fabrication method leads to a path toward electronic devices on flexible substrates.

42 ENGINEERING↗
DOE OSTI2021

Dynamic Strength of Copper at High Pressures Using Pressure Shear Plate Experiments

Measurement of strength at high pressures is critical to understanding the behavior of materials subjected to extreme loading conditions. Recent developments have extended the pressure shear plate impact (PSPI) technique to the high-pressure regime. Such experiments provide a unique opportunity to extract the complete stress-strain behavior of materials at relatively high pressures. The modified technique includes a new fiber-optic heterodyne transverse velocity interferometer system and new analysis methods to account for the inelastic response of the anvil plates. In this study, PSPI experiments are conducted on oxygen-free high conductivity (OFHC) copper at pressures ranging from 10 to 43 GPa and at strain rates of ~10 5 s -1 . Complete stress-strain curves of copper are obtained using a hybrid methodology that relies on numerical simulations and particle velocity records gathered in these experiments. Experiments are conducted at similar pressures and strain rates using two types of anvils that undergo different levels of plastic strains: tool steel and tungsten carbide, to check the robustness of the hybrid method. The behavior of copper at these high pressures and strain rates is compared with previous literature data, and the effect of pressure and strain rate on the strength behavior of copper are discussed. Here, it was observed that the rate of change in yield strength change in pressure was 2.5 times the rate of change of shear modulus with pressure. The strength models that predict the response of copper at these extreme conditions are also examined and validated.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Physical structure of constitutional isomers influences antiproliferation activity of thiosemicarbazone-alkylthiocarbamate copper complexes

A series of hybrid thiosemicarbazone-alkylthiocarbamate copper complexes with similar electronic environments but distinct physical structures have been prepared, characterized, and evaluated for antiproliferation activity. The complexes include the constitutional isomers (1-phenylpropane-1-imine-(O-ethylthiocarbamato)-2-one-(N-methylthiosemicarbazonato))copper(II) (CuL 1 ) and (1-phenylpropane-1-one-(N-methylthiosemicarbazonato)-2-imine-(O-ethylthiocarbamato))copper(II) (CuL 2 ) along with (1-propane-1-imine-(O-ethylthiocarbamato)-2-one-(N-methylthiosemicarbazonato))copper(II) (CuL 3 ). Complexes CuL 1 and CuL 2 differ in the positions of the pendent thiosemicarbazone (TSC) and alkylthiocarbamate (ATC) moieties on the 1-phenylpropane backbone. Complex CuL 3 employs a propane backbone with the TSC in the 2-position as in CuL 1 . The isomer pair CuL 1 and CuL 2 have equivalent electronic environments with indistinguishable Cu II/I potentials (E 1/2 = -0.86 V vs. ferrocenium/ferrocene) and electron paramagnetic resonance (EPR) spectra (g ∥ = 2.26, g ⊥ = 2.08). The electronic structure of CuL 3 has a similar E 1/2 of -0.84 V and identical EPR parameters to CuL 1, 2 . Single crystal X-ray diffraction studies confirm a consistent donor environment with no substantial variation in the Cusingle bondN or Cusingle bondS bond distances and angles between the complexes. The antiproliferation activities of the CuL 1–3 were evaluated against the lung adenocarcinoma cell line (A549) and nonmalignant lung fibroblast cell line (IMR-90) using the MTT assay. CuL 1 had the highest A549 activity ( A549 EC 50 = 0.065 μM) and selectivity ( IMR-90 EC 50 / A549 EC 50 = 20). The constitutional isomer CuL 2 displayed decreased A549 activity (0.18 μM) and selectivity (10.6). The complex CuL 3 displayed activity (0.009 μM) similar to CuL 1 but with a lack of selectivity (1.0). Cellular copper loading determined by ICP-MS was consistent with the activity and selectivity trends. The complexes CuL 1–3 did not induce reactive oxygen species (ROS) generation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2013

Three tetranuclear copper(II) cluster-based complexes constructed from 4-amino-1,2,4-triazole and different aromatic carboxylates: Assembly, structures, electrochemical and magnetic properties

Three new tetranuclear copper(II) cluster-based complexes constructed from 4-amino-1,2,4-triazole (atrz) and three types of aromatic carboxylates, [Cu{sub 4}({mu}{sub 3}-OH){sub 2}(atrz){sub 2}(DNBA){sub 6}] (1), [Cu{sub 4}({mu}{sub 3}-OH){sub 2}(atrz){sub 2}(1,3-BDC){sub 3}]{center_dot}2H{sub 2}O (2) and [Cu{sub 4}({mu}{sub 3}-OH){sub 2}(atrz){sub 2}(SIP){sub 2}]{center_dot}4H{sub 2}O (3) (HDNBA=3,5-dinitrobenzoic acid, 1,3-H{sub 2}BDC=1,3-benzenedicarboxylic acid and NaH{sub 2}SIP=sodium 5-sulfoisophthalate), have been hydrothermally synthesized and structurally characterized. Complex 1 displays a single-molecular Cu{sup II}{sub 4} cluster structure, which is further connected by the intermolecular hydrogen-bonding interactions to form a 2D supramolecular layer. In 2, there also exist tetranuclear Cu{sup II}{sub 4} clusters, which are linked by the 1,3-BDC anions to give a 3D NaCl-type framework. In 3, the Cu{sup II}{sub 4} clusters are connected by the carboxyl and sulfo groups of SIP anions to generate 3D (4,8)-connected framework with a (4{sup 10}{center_dot}6{sup 14}{center_dot}8{sup 4})(4{sup 5}{center_dot}6){sub 2} topology. The atrz ligand conduces to the construction of tetranuclear copper(II) clusters and the carboxylates with different non-carboxyl substituent show important effects on the final structures of the title complexes. The electrochemical and magnetic properties of 1-3 have been investigated. - Graphical abstract: Three tetranuclear copper(II) cluster-based complexes based on different carboxylates have been synthesized under hydrothermal conditions. The carboxylate anions play a key role in the formation of three different structures. Highlights: Black-Right-Pointing-Pointer Three new tetranuclear copper(II) cluster-based complexes have been obtained. Black-Right-Pointing-Pointer The atrz conduces to the construction of tetranuclear copper(II) clusters. Black-Right-Pointing-Pointer Carboxylates show important effect on the structures of title complexes. Black-Right-Pointing-Pointer Magnetic properties and electrochemical behaviors have been reported.

36 MATERIALS SCIENCE↗
DOE OSTI2021

A preliminary investigation into the electrodeposition and synthesis of radiopure Copper–Chromium alloys for rare-event physics detector systems

Current investigations into neutrinoless double beta decay and the direct detection of dark matter require increasingly sensitive detector systems that demand ultra-low background materials. These requirements have previously been attained using ultra-radiopure electroformed (EF) copper. However, pure copper possesses high ductility and relatively low strength, which necessitates the need for large amounts of material and extra care during fabrication to help minimize galling and mechanical failure. Furthermore, we investigate an alloying alternative to pure EF copper by examining low wt% copper chrome (Cu–Cr) solid solution alloys, with inquiries into alloy hardness, strength, and radiopurity. Alloyed Cu–Cr layered samples are shown to exhibit significantly increased hardness compared to EF copper, for example showing a 50% increase in exhibited hardness using less than 1% Cr by weight, with limited negative impact to the material’s radiopurity.

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