Range Of Cu Content Research Articles

COMMON REED (PHRAGMITES AUSTRALIS (CAV.) TRIN. EX STEUD.) AS BIOACCUMULATOR OF FE, MN, CU ON BIO-ENGINEERING FACILITIES OF POLTAVSKY MINING AND PROCESSING PLANT

The goal of this study was evaluation of the total phytomass of reed per unit of square on each bio-engineering facilities (BIF), its distribution between aboveground and underground parts, biological uptake of some heavy metals (Fe, Mn, Cu) by the total reed phytomass and its separate organs. Objects of research were: reed biogeocenoses; subject of study – reed phytomass per square unit and content of heavy metals (Fe, Mn, Cu) in reed organs each BIF. Study was conducted in July 2021 on the territory of six BIF of Poltavsky Mining and Processing Plant, where clarified waste waters are pumped up. On each BIF 5 experimantal plots were established, where number of reed’s individuals, number of shoots per square unit were calculated and samples of reed’s organs were collected. Calculation of reed’s phytomass were conducted for each BIF: for 1 shoot, 1 individual, thickets of reed per square unit (m2, ha). Content of heavy metals were measured after ashing at temperature 300ºС, by the method of emissive spectrum analysis on spectrographe ICP-28. It was shown that on all BIF reed was characterized by significant aboveground phytomass (t·ha-1): BIF-1а – 11,1; BIF- 1b – 9,2; BIF-2 – 10,6; BIF-3 – 29,7; BIF-4 – 15,4; BIF-5 – 13,8. Values of underground phytomass significantly exceeded aboveground one (t·ha-1): BIF-1а – 55,4; BIF-1b – 50,2; BIF-2 – 72,5; BIF-3 – 232,8; BIF-4 – 106,5; BIF-5 – 79,0. The parts of underground and aboveground phytomass of reed were: on BIF-1а – 83,3 and 16,7%; BIF-1b – 84,5 and 15,5%; BIF-2 – 87,2 and 12,8%; BIF-3 – 88,7 and 11,3%; BIF-4 – 87,4 and 12,6%; BIF-5 – 85,1 and 14,9% respectively. On all BIF general regularity was observed – significantly higher Fe content in underground organs than in aboveground ones. Range of Fe content on different BIF were (mkg·kg-1): stems – 143 ± 13–225 ± 20; leaves – 529 ± 50–1 000 ± 95; inflorescens – 67 ± 7–273 ± 30; rhizomes with roots – 3 584 ± 342–6 700 ± 655. Ranged row of reed organs according with Fe content was: rhizomes with roots > leaves > inflorescens > stems. Range of Mn content on different BIF were (mkg·kg-1): stems – 14 ± 1–100 ± 10; leaves – 75 ± 8–385 ± 35; inflorescens – 13 ± 1–96 ± 10; rhizomes with roots – 137 ± 13–700 ± 63. Ranged row of reed organs according with Mn content, as a rule, was the same as for Fe. Average Cu content in reed’s organs was approximately in 10 times less in comparison with Mn, and in 100-1000 times less in comparison with Fe. Range of Cu content on different BIF were (mkg·kg-1): stems – 3 ± 0,2–7 ± 0,7; leaves – 2 ± 0,2–8 ± 0,8; inflorescens – 4 ± 0,4–9 ± 0,9; rhizomes with roots – 5 ± 0,5–23 ± 2,5. It was made a conclusion that underground phytomass of reed – multiyear rhizomes with roots – has determining influence on accumulation of all investigated heavy metals by reed.

Variation in crystal structure of <i>Ln</i><sub>2</sub>Ni<sub>1−</sub><i><sub>x</sub></i>Cu<i><sub>x</sub></i>O<sub>4+δ</sub> (<i>Ln</i>: La, Pr, Nd, Sm, Eu, and their solid solution) based on type of <i>Ln</i>: Relationship between crystal structure and tolerance factor

The variation in the crystal structure of Ln2Ni1−xCuxO4+δ, which has great potential as a new cathode material for solid oxide fuel cells, based on the type of Ln (La, Pr, Nd, Sm, Eu, and their solid solution), was investigated. For Ln with ionic radius larger than 1.21 Å (1 Å = 0.1 nm), a single-phase K2NiF4 structure called T-phase was prepared for 0.0 ≤ x ≤ 1.0. For Ln with ionic radius between 1.21 and 1.15 Å, the crystal structure changed from single T-phase to single Nd2CuO4 structure called T′-phase, through the mixture of T-phase and T′-phase, along with increasing Cu content. The range of Cu content, in which the mixture phase was obtained because of the miscibility gap, increased with the decreasing size of Ln. The single T-phase was never prepared for Ln with ionic radius below 1.15 Å. Rough tendencies were observed, indicating that the single T-phase was obtained or was not prepared if the tolerance factor was above or below 0.865, respectively. The mixture of T-phase and T′-phase was obtained because of the miscibility gap by decreasing the tolerance factor slightly below about 0.865. The T-phase was never generated by decreasing the tolerance factor any further. The change of the crystal structure by Cu content and kind of Ln can also be explained by using Jahn–Teller effect of Cu2+ ion.

The Antimicrobial Activity and Characterization of the Cast Titanium Copper Alloys with Variations of Copper Content

The effect of Cu addition on antimicrobial activity of Cast Ti-Cu Alloys against Staphylococcus aureus were studied. The Ti-Cu alloys were prepared with a variation of 0.5, 1, 2, 3, 4, 8 and 10 wt% of copper. Pure Ti metal was also prepared and tested as a comparison. The antibacterial was performed by killing activity test of colony forming unit (CFU) method with variation of contact time. Optical microscope observation, XRD, and the Vickers hardness test were carried out to characterize the investigated alloys. The results showed that Ti-Cu alloys were able to decrease the amount of bacteria by time. However, the activity of killing of bacteria in the varied range of Cu content did not show significantly different result. The highest bacterial kill ability in the alloy was observed in addition of 3 wt% Cu.

Copper isotope behavior during extreme magma differentiation and degassing: a case study on Laacher See phonolite tephra (East Eifel, Germany)

Copper (Cu) isotopic analyses were performed on a set of samples from the Laacher See tephra (LST) (Eifel, Germany) to investigate whether Cu isotopes are fractionated during extreme magma differentiation and degassing. The LST represents a continuous fractional crystallization series from parental basanite through mafic to highly differentiated phonolites. Samples analyzed here include phonolites of variable degrees of differentiation, phonolite–basanite hybrid rocks formed by mixing basanite and phonolite magmas, and basanite-derived mega-crystals (i.e., clinopyroxene, amphibole, phlogopite). In addition, we analyzed a series of mafic parental lavas from surrounding volcanic centers to constrain the Cu isotopic features of the Eifel mantle. Mafic phonolites show strong depletion in Cu compared to their parental basanites from ~50 to ~3 ppm, indicating sulfide fractionation during the basanite-to-phonolite differentiation. Mass balance calculations, based on the most Cu-rich hybrid rock (δ65Cu = −0.21 ‰, [Cu] = 46.2 ppm), show that the parental basanite magmas have δ65Cu of ca. −0.21 ‰, lighter than those of the mafic phonolites (~0.11 ‰). This suggests that sulfide fractionation preferentially removes the lighter Cu isotope (63Cu) in S-saturated magmas. By contrast, all phonolites have a limited range of Cu contents (1.1 to 4.0 ppm) with no systematic variations with S, suggesting that Cu is not controlled by sulfide fractionation during the evolution of mafic to highly differentiated phonolites. The identical δ65Cu values (0.11 ± 0.03 ‰, 2SD, n = 10) of the phonolites, irrespective of highly diverse composition and extents of differentiation, indicate that fractional crystallization of silicates (e.g., plagioclase, sanidine, amphibole, pyroxene, olivine), Fe–Ti-oxides and phosphate (e.g., apatite) generates insignificant Cu isotope fractionation. The lack of correlations between δ65Cu and volatile contents (e.g., S, Cl) in the LST sequence implies that volcanic degassing causes no detectable Cu isotope fractionation of igneous rocks. Eifel basalts and mega-crystals have variable δ65Cu (−0.18 to 0.21 ‰) that are uncorrelated to MgO and Cu, suggesting that such variations were not caused by differentiation but reflect the Cu isotopic heterogeneity of the Eifel mantle source due to metasomatism by fluids derived from hydrothermally altered oceanic lithosphere.

Effect of magnetism on lattice dynamical properties in the Ni–Cu alloy from first principles

We have studied the lattice dynamical properties of the magnetic intermetallic Ni1−xCux alloy within the framework of density functional perturbation theory using a mixed-basis pseudopotential method and the self-consistent virtual crystal approximation for modeling the alloy. A transition from a ferromagnetic (FM) to a non-magnetic (NM) state is found at a critical concentration xc=0.45. Phonon spectra as a function of x for both FM and NM states obtained for the entire range of Cu content show good agreement with available experimental data. The magnetic order for x<xc has only a subtle influence on the phonon modes, but induces important changes in the dynamical coupling of first- and second-nearest neighbor bonds. While variations in the first-nearest neighbor coupling are linked to structural, chemical and magnetic changes along the alloy series, the second-nearest neighbor is almost entirely sensitive to the magnetic order only.

Cu Insertion Into the Mo12 Cluster Compound Cs2Mo12Se14: Synthesis, Crystal and Electronic Structures, and Physical Properties

Mo-based cluster compounds are promising materials for high-temperature thermoelectric applications due to their intrinsic, extremely low thermal conductivity values. In this study, polycrystalline cluster compounds Cs2CuxMo12Se14 were prepared for a wide range of Cu contents (0 ≤ x ≤ 2). All samples crystallize isostructurally in the trigonal space group R3̅. The position of the Cu atoms in the unit cell was determined by X-ray diffraction on a single-crystalline specimen indicating that these atoms fill the empty space between the Mo-Se clusters. Density functional theory calculations predict a metallic ground state for all compositions, in good agreement with the experimental findings. Magnetization measurements indicate a rapid suppression of the superconducting state that develops in the x = 0.0 sample upon Cu insertion. Transport properties measurements, performed in a wide temperature range (2-630 K) on the two end-member compounds x = 0 and x = 2, revealed a multiband electrical conduction as shown by sign reversal of the thermopower as a function of temperature.

Microstructure and transformation temperatures in rapid solidified Ni–Ti alloys. Part II: The effect of copper addition

Ternary rapidly solidified alloys were produced and tested in this research work. Cu was added to a near equiatomic Ti49Ni51 alloy, by substituting Ni. Three compositions were considered: Ti49Ni51−xCux (x=5, 15, 25). Samples with the shape of cones were obtained, in order to test the effects of different rapid solidification rates. The aim of this research is to analyze the use of rapid solidification in the low regime of cooling rates (102–103K/s), which is much more suitable for industrial processes than the extremely high cooling rates (such as melt spinning). We found that, as Cu was added into the alloy, the transformation temperatures rapidly decline and they reach a minimum between 5 and 15at.% of Cu. Then, they begin to increase and they are comparable with those of the binary alloy when Cu is equal to 25at.% A higher cooling rate lowers the transformation temperatures, showing an opposite effect respect to Cu addition. Moreover, the Cu addition reduces the transformation hysteresis. Some precipitates were found in the ternary alloys and Ni and Cu showed a linear exchanging tendency in the precipitates, in the explored range of Cu content.

Selective hydrogenolysis of xylitol to ethylene glycol and propylene glycol over copper catalysts

CuSiO2 catalysts were prepared by homogeneous deposition–precipitation with a wide range of Cu contents (8.8–100wt%) and Cu particle sizes (2.1–111.1nm). These catalysts were evaluated in the selective hydrogenolysis of biomass-derived xylitol to ethylene glycol and propylene glycol under the promotion of Ca(OH)2 base. Their catalytic activity and selectivity to the two glycols depended strongly on the Cu particle sizes, which increased with the particle sizes and reached the maximum values at around 20–35nm. Such size effects are apparently attributed to the effects on the dehydrogenation and hydrogenation activities of the Cu catalysts, and consequently on the xylitol hydrogenolysis pathways, reflecting the structural requirement for the xylitol hydrogenolysis. The effects of the reaction parameters including H2 pressure (0–8.0MPa), temperature (433–493K) and pH values (7.0–12.4, adjusted by changing the amount of Ca(OH)2) were examined. These effects confirmed the reaction pathways previously proposed for the xylitol hydrogenolysis to the two glycols, involving the dehydrogenation of xylitol to xylose on Cu as the rate-determining step, followed by the retro-aldol condensation of xylose with Ca(OH)2 to glycolaldehyde and glyceraldehyde, and their subsequent hydrogenation to ultimately form glycols in competition with their side reactions to glycolic acid and lactic acid in the presence of Ca(OH)2. Upon optimizing the reaction conditions (473K, 6.0MPa H2 and sufficient Ca(OH)2), nearly 100% xylitol conversion and 54.4% combined selectivity to ethylene glycol and propylene glycol were obtained on CuSiO2 with Cu size of 35.7nm, comparable to those on the previously reported Ni- and Ru- based catalysts. Clearly, this study provides directions for the design of more efficient Cu catalysts and the optimization of the reaction parameters toward the efficient polyol hydrogenolysis into glycols.

Fabrication of wide-bandgap β-Cu(In,Ga) 3 Se 5 thin films and their application to solar cells

Cu(In,Ga) 3 Se 5 is a candidate material for the top cell of Cu(In,Ga)Se 2 tandem cells. This phase is often found at the surface of the Cu(In,Ga)Se 2 film during Cu(In,Ga)Se 2 cell fabrication, and plays a positive role in Cu(In,Ga)Se 2 cell performance. However, the exact properties of the Cu(In,Ga) 3 Se 5 film have not been extensively studied yet. In this work, Cu(In,Ga) 3 Se 5 films were fabricated on Mocoated soda-lime glass substrates by a three-stage co-evaporation process. The Cu content in the film was controlled by varying the deposition time of each stage. X-ray diffraction and Raman spectroscopy analyses showed that, even though the stoichiometric Cu/(In+Ga) ratio is 0.25, Cu(In,Ga) 3 Se 5 is easily formed in a wide range of Cu content as long as the Cu/(In+Ga) ratio is held below 0.5. The optical band gap of Cu 0.3 (In 0.65 Ga 0.35 ) 3 Se 5 composition was found to be 1.35eV. As the Cu/(In+Ga) ratio was decreased further below 0.5, the grain size became smaller and the band gap increased. Unlike the Cu(In,Ga)Se 2 solar cell, an external supply of Na with Na 2 S deposition further increased the cell efficiency of the Cu(In,Ga) 3 Se 5 solar cell, indicating that more Na is necessary, in addition to the Na supply from the soda lime glass, to suppress deep level defects in the Cu(In,Ga) 3 Se 5 film. The cell efficiency of CdS/Cu(In,Ga) 3 Se 5 was improved from 8.8 to 11.2% by incorporating Na with Na 2 S deposition on the CIGS film. The fill factor was significantly improved by the Na incorporation, due to a decrease of deep-level defects.

Respiration parameters determined by the ISO-17155 method as potential indicators of copper pollution in vineyard soils after long-term fungicide treatment

This study seeks to determine the impact of copper-based fungicides on the respiration of vineyard soils. The ISO-17155 is an international standard recommended for monitoring soil quality by the evaluation of the effects of pollutants on soil microbial activity. Respiration curves and derived parameters [i.e., basal respiration (RB), substrate-induced respiration (RS), lag time (tlag), growth rate (μ), time to the peak maximum (tpeakmax), respiratory-activation quotient (QR), and the cumulative O2 consumption (CR)] were determined from 95 vineyard soils that covered a wide range of Cu contents. Statistical analyses showed that most of the variance of the ISO-17155 parameters was due to soil pH and organic C content, but not to the Cu pollution. When the parameters were expressed as a function of soil organic C content, the effect of soil Cu content was found to be significant on RS and tpeakmax but not on RB and CR. The results indicated that threshold values of total (CuT) and exchangeable (CuEX) contents indicative of soil Cu pollution cannot be established. However, adequate management practices resulting in soil organic C contents>2% and pH>5.5 are recommended for preserving vineyard soil quality.

Development of Polyimide/SMA Thin-Film Actuator

Ti-Ni-Cu shape memory alloy (SMA) thin films were sputter-deposited on heated polyimide substrates. The (Ni,Cu) rich Ti-Ni-Cu films deposited at a substrate temperature of 543 K were found to possess a high martensitic transformation temperature above room temperature over a wide range of Cu content from 7 to 23 at%, which allows stable production of actuators that operate at room temperature. Additional deposition of a Cu film onto the Ti-Ni-Cu films facilitated the soldering of wires onto the actuators and also decreased the power consumption and response time of the actuator. The force of a polyimide/Ti-Ni-Cu SMA actuator could be increased merely by increasing the thickness of the polyimide film. An actuator composed of a 125 m thick polyimide film and an 8 m thick TiNiCu film was able to lift a 13.5 g weight. Furthermore, a Ti-Ni-Cu film could be pattern etched on a polyimide film to produce a circuit. The results indicate that a polyimide/SMA film actuator is a promising simple actuator that can be produced by simply cutting out an appropriately shaped piece with scissors or by punching and then connecting the two edges to a battery by soldering.

Copper and phosphorus effect on residual embrittlement of irradiated model alloys and RPV steels after annealing

The dependence of the recovery of the transition temperature shift after annealing (475 °C, 100 h) on copper and phosphorus contents has been studied on irradiated reactor pressure vessel (RPV) materials. A set of model alloys with low nickel content, lower than 0.2 mass%, was used for the study. Copper and phosphorus contents were varied in a wide range: 0.005–0.99 and 0.002–0.039 mass%, respectively. Recovery efficiency has been estimated by the value of residual embrittlement after annealing, measured in terms of a shift in transition temperature ( Δ T K res ). A comparison of the results obtained on model alloys with data for VVER-440 RPV materials has also been carried out. Comparative analysis has confirmed the conclusion that Δ T K res is independent of phosphorus content while the effect of copper on Δ T K res is not significant for typical VVER-440 RPV materials with a typical range of Cu contents between 0.10 and 0.24 mass%. However, for model alloys with a wider range of copper content, copper mainly controls the value of Δ T K res .

Influence of Cu content on electronic transport and shunting behavior of Cu(In,Ga)Se2 solar cells

The paper presents the structural and electrical characterizations of Cu(In,Ga)Se2 thin films and thin-film solar cells realized with different Cu contents in the absorber material. It is shown that the bulk resistivity of the Cu(In,Ga)Se2 thin films (measured in coplanar geometry) dramatically increases with decreasing Cu content. Simultaneously, the shunt resistance Rp of the Cu(In,Ga)Se2 solar cells increases with decreasing Cu content in the absorber material. For a wide range of Cu contents, the resistivity of the thin films is directly proportional to Rp of the solar cell made from the same absorber material. We propose that Rp in Cu(In,Ga)Se2 solar cells originates from highly localized shunt regions in the absorber material. The higher Rp of cells made from Cu-poor material is then due to the high resistivity of the embedding Cu-poor material resistively suppressing extensive current flow towards these shunt regions. Further, we observe an increase of the film resistivity by two orders of magnitude if the Cu(In,Ga)Se2 absorbers are produced using a Na blocking layer on the glass substrate. However, the high resistivity of these Na-free samples does not go along with an increase of Rp in the corresponding solar cells, indicating that the high resistivity of Na-free Cu(In,Ga)Se2 results from electrostatic barriers at the grain boundaries and is not a bulk property.

Hard nanocomposite Ti–Cu–N films prepared by d.c. reactive magnetron co-sputtering

Two series of Ti–Cu–N films containing 0–10 at.% Cu were deposited by d.c. magnetron co-sputtering from two elemental targets in Ar–N 2 gas mixture by biasing the Si (100) substrates with −150 V and +35 V, respectively. The influence of Cu content and deposition conditions were examined with regard to the microstructure, morphology, mechanical and tribological properties of these films. All films deposited on −150 V biased substrates exhibited a pronounced TiN (111) texture, while this texture was found to weaken in the films deposited on +35 V biased substrates with the addition of a small amount of Cu. Hardness enhancement from ∼22 GPa for pure TiN film to ∼30 GPa upon the addition of Cu was observed in both cases. However, in the case of −150 V bias hardness enhancement occurred in a relatively wide range of Cu content (<10 at.% Cu), whereas at +35 V bias it was only observed in a narrow range of Cu content of approximately up to 2.81 at.%. The dry friction coefficient against SUS440C steel ball decreased from high value of ∼0.8, corresponding to TiN film, to a low value of approximately 0.2 in some Ti–Cu–N films with enhanced hardness.

Surface properties of CuCl 2/AC catalysts with various Cu contents: XRD, SEM, TG/DSC and CO-TPD analyses

Surface properties of CuCl 2/activated carbon (AC) catalyst for dimethyl carbonate synthesis were studied by CO-TPD, XRD, SEM and thermogravimetry (TG)/differential scanning calorimetry (DSC) with varying Cu contents. CuCl 2/AC catalysts were prepared by impregnating AC with CuCl 2–ethanol solution in the range of Cu content from 2.8 to 18.7 wt.%. CuCl 2·2H 2O crystalline phase as active sites was gradually increased with an increase in Cu content. Appearance of CuCl 2·2H 2O was clearly identified by XRD and SEM. In relatively low Cu contents, 4.6 and 9.9 wt.%, CuCl 2·2H 2O was not detected in XRD. This indicates the formation of good dispersion of CuCl 2 compounds on activated carbon. However, DSC result revealed that CuCl 2·2H 2O was formed in multi-layers for the catalyst with Cu content more than 9.9 wt.%, which limit the catalyst activity. This fact was also strongly supported by CO-TPD experiment. The two CuCl 2/AC catalysts having Cu contents of 4.6 and 9.9 wt.% showed no difference in CO adsorption amount in TPD experiments.

Spectroscopic characterisation of Cu–Al2O3 catalysts for selective catalytic reduction of NO with propene

Copper–aluminium mixed oxide catalysts (Cu–Al2O3) for selective reduction of NO with propene (C3H6-SCR) were characterised as a function of Cu content. The results from different techniques, Cu K-edge and Cu L3-edge XANES, diffuse reflectance UV–Vis, XPS, and XRD were combined to develop coherent description of the phases present and cation site distribution in Cu–Al2O3. Both the bulk and the surface of Cu–Al2O3 consist of Cu2+ cations at tetrahedral or octahedral sites of the Al2O3 matrix, forming an aluminate phase in a wide range of Cu content (1–30 wt.%). Cu L3-edge XANES analysis succeeded in quantifying the fraction of tetrahedral and octahedral Cu2+ ions; the fraction of octahedral Cu2+ decreased as Cu concentration increased. The catalytic activity for C3H6-SCR per surface area of the catalysts increased as surface Cu2+ concentration increased, indicating that Cu2+ ions in the aluminate phase are responsible for the activity. The activity per surface Cu2+ decreased as surface Cu2+ concentration increased, which coincides with the decrease in the fraction of octahedra. The Cu2+ cations in octahedral sites should be responsible for the higher intrinsic activity.

銅‐モリブデン系複合材料の機械的特性

For applicability in the field of semiconductor, it is important that the thermal expansion coefficient of heat sink materials approximates to those of semiconductor chip and peripheral materials. In addition, high thermal conductivity also is required. The authors have studied a composite of molybdenum (Mo) and copper (Cu) prepared by two kinds of method, the mixing method (M/CM) and the cladding method (L/CM). The mechanical and thermal properties of these Cu-Mo composites can be controlled by varying the composition ratio.In this paper, mechanical properties of the Cu-Mo composites were investigated. The thermal expansion coefficient α of M/CM increased with increase in copper content. The mean measured values of α in the temperature of about 30°C nearly corresponded with those calculated from Turner's equation and Kerner's equation. The observed anisotropy in α values was maximum for 50 mass% Cu content. The measured values of tensile strength, Young's modulus, Poisson's ratio and Vickers hardness showed a behavior similar the linear law of a mixture rule, but their values were a little smaller than the values calculated by the rule. The elongation and Erichsen value were discontinuous with the rule.The α of L/CM was increased with an increase in Cu content. With the rise in temperature, Mo of the middle layer strongly controlled the thermal expansion. The mean measured values of α in the temperature of about 30°C were smaller than the values calculated by the mixture rule of material dynamics. Comparing L/CM with M/CM, the α values of L/CM were smaller than those of M/CM over the entire range of Cu content.

Stoichiometry control over a wide composition range of sputtered CuGaxIn(1−x)Se2

Films of CuGaxIn(1−x)Se2 (CGIS) have been grown by rf sputtering from stoichiometric single targets with different Ga/In ratios. Adjusting growth temperature and argon pressure we are able to deposit films with a wide range of Cu contents: From CGIS Cu-poor (16 at. %) to Cu2Se. Reevaporation of (Ga,In)2Se3 binaries is observed when substrate temperature is increased at a constant argon pressure (20 mTorr). An increase in Ar pressure from 5 to 150 mTorr at a growth temperature of 450 °C, produces a decrease in Cu atomic percentage from 24% to 16% due to a preferential diffusion of Cu sputtered atoms in the plasma. The relevant film properties of the analyzed films are found to be ruled by the Cu content. Graded composition absorbers with adequate physical properties for the fabrication of photovoltaic devices are grown with a proper choice of growth parameters.

Material Characterization of Rapidly Solidified Ti-Ni-Cu Alloys

AbstractMaterial properties of of rapidly solidified(RS),Ti5øNi5ø-xCux(X=O-2Oat%) alloys,i.e., thermoelasatic transformation temperature,transformation strain vs. temperature hysteresis, strength.ductility,themal fatigue resistance and corrosion resistance etc. were investigated. Specimens of thin ribbon were prepared by using melt-spinning machine with single Cu rolls at the cooling rate of about 40 m/sec. In the range of Cu content over lOat%,rapidly solidified (RS)ribbons were producible as a very thin plate and showed high ductility(i.e.180° bending). From the measurements of transformation strain vs. temperature hysteresis under small stress a bout 60MPa,transformation strain shows the maximum at Cu=5at%,and its transformtion temperature range nΔ(=Af-Mf) decreased with increasing Cu content to minimum value of 6.5K at Cu=17 at%. Thermal fatigue resistance was improved very much about ten times,futhermore,corrosion resistance was also improved over 100 times as much as conventionally processed(i.e. melting→ mechanically worked) material. It can be concluded that the functional superioity of RS meltspun Ti5øNi5ø-xCux ribbon exists in the range of Cu content over 10 at%. The reason of abovementioned remarkable improvements of material properties of RS TiNiCu alloys is discussed by relating with the observed unique fine columnar microstructures having strong crystal anisotropy and homogeneouss smooth surface.

Distribution of Cu in the basic hornfelses of the Land's End aureole, Cornwall, and other chemically similar rocks

During the metasomatic development of Fe-Mg hornfelses (and possibly Ca hornfelses) from basic hornblende hornfelses, Cu was depleted. The mobilized Cu may now reside in associated cupiferous lodes. Distribution of Cu in basic igneous rocks (new average 115 ppm) and ortho-amphibolites (new average 107 ppm) is surveyed and compared. The greater range of Cu content in ortho-amphibolites reflects variable, localized mobility during metamorphism.