Higher Ts Research Articles

Evolution of the paleo-Daesan Bay (Nakdong River, South Korea) as a result of Holocene sea level change

AbstractTo explore sea level transgression in low-lying inland areas and its possible influence on prehistoric cultures, we investigated the physical and geochemical features of 20-m-long sedimentary cores from the previously seawater-filled Daesan Basin located in the middle reach of the present Nakdong River in Korea as proxies for seawater transgression deep inland areas due to Holocene sea level rise. Based on the relationships among grain size, total sulfur content (TS%), and carbon/sulfur (C/S) ratio, the first transgressive event was detected at ca. 8500 cal yr BP, caused by seawater influx along the present Nakdong River. Higher TS% (0.8–1%) and interbedded fossil oysters at 8000–6000 cal yr BP indicate marine environments, supporting a paleo-Daesan Bay with water depth of ~10–8 m. The common peaks in TS%, in both inland paleo-Daesan Bay and a present coastal area (Suncheon Bay) in southern Korea (e.g., at 3200 and 4700 cal yr BP), may indicate intervals of higher salinity, which suggests simultaneous responses to changes in sea level or hydroclimate. The duration of marine environment (paleo-Daesan Bay) in the remote inland from ca. 8000–3200 cal yr BP provides an analog for inland paleo-bay studies in East Asia.

Miocene coals in the Hanoi Trough, onshore northern Vietnam: Depositional environment, vegetation, maturity, and source rock quality

The Hanoi Trough in northern Vietnam forms the landward extension of the large Song Hong Basin in the South China Sea. Several gas and condensate discoveries have been made in the offshore part while exploration in the Hanoi Trough has been less successful. Encountered hydrocarbons suggest a terrigenous source rock, the most likely candidate being Miocene coals. The composition of these is poorly documented in the public domain, but in the Hanoi Trough with a thinner Cenozoic succession numerous Miocene coal beds have been penetrated by several wells. The current study examines by organic petrography, geochemistry, and sedimentology the depositional environment, paleo-vegetation, thermal maturity and source rock potential of Miocene coal samples from two about 1000 m fully cored wells in the Hanoi Trough. The sedimentological facies, dinoflagellate cyst content and pyrite nodules suggest the coals were formed in coastal mires, in particular the younger section, testifying to an overall relative sea-level rise in the Miocene. This is supported by abundant framboidal pyrite and high TS contents in the coals. Dominance of huminite in all samples suggests water-logged mire conditions while abundant funginite and high concentrations of hopanes indicate high bacterial and fungal activity. Reduced fluorescence, oxidation rims, and elevated reflectance of resinite in a sample with concentrations of liptinite composed of resinite, cutinite, suberinite, sporinite and liptodetrinite might suggest the liptinite-enrichment was the result of degradational removal of less resistant organic matter. Biomarkers indicate the mire vegetation consisted of gymnosperms related to Podocapaceae or Cupressaceae, and perhaps Pinaceae. Presence of angiosperms is indicated by oleanane and aromatic oleananes, lupanes and ursanes. An unknown diterpane derived from Araucaria nemorosa (conifer in the Araucariaceae family) and/or Araucaria cunninghamii (pine) may be the first occurrence in a geological sample. The coals are of lignite to sub-bituminous A rank and are thermally immature with regard to hydrocarbon generation. They are today not at maximum burial depth due to c. 480–1450 m of Miocene uplift before reburial in Plio-Pleistocene time. HImax values around 200 mg HC/g TOC reveal the coals primarily are gas-prone, but exsudatinite in cleats in huminite and cell lumens in funginite is evidence for in situ generation from labile macerals. Oil droplets in cleats/cracks suggest migration of liquid hydrocarbons from deeper buried source rocks and are indicative of a working petroleum system in the Hanoi Trough.

Effect of Thermal Hydrolysis Pretreatment on Anaerobic Digestion of Protein-Rich Biowaste: Process Performance and Microbial Community Structures Shift

To reveal the effects of thermal hydrolysis (TH) pretreatment (THPT) on anaerobic digestion (AD) of protein-rich substrates, discarded tofu was chosen as the object, and its batch AD tests of tofu before and after being subjected to TH at gradually increasing organic loads were carried out and the AD process characteristics were compared; furthermore, its continuous AD tests without and with THPT were also conducted and the difference of the microbial community structures was investigated. The results showed that, during AD of protein-rich tofu with increase in the organic load, inhibition from severe acidification prior to accumulation of ammonia nitrogen (AN) occurred. THPT helped overcome the acidification inhibition present in batch AD of tofu at such a high TS content of 3.6%, to obtain the maximum methane yield rate of 589.39 ml·(gVS)−1. Continuous AD of protein-rich tofu heavily depended on ammonia-tolerant hydrogenotrophic methanogens and bacteria. The continuous AD processes acclimated by HT substrates seemed to be resistant to severe organic loads, by boosting growth of ammonia-tolerant microorganisms, above all methylotrophic methanogens such as the genera RumEnM2 and methanomassiliicoccus. The process response of continuous AD of HT tofu was hysteretic, suggesting that a sufficiently long adaptation period was required for stabilizing the AD system.

A Ilha de calor: Relação entre o uso e cobertura do solo e a Temperatura de Superfície com base em geoprocessamento em Arapiraca-Alagoas, Brasil

This work aimed to analyze the formation of islands of heat and coolness in the center of the city ​​of Arapiraca - Alagoas, through data from Landsat 8 OLI/TIRS images, scene 215/067, associated with the dynamics of land use and land cover with a time frame in the years 2013, 2017 and 2018. A methodology consisted of literature review, survey of pre-existing data, processing of images and analysis of land use and cover and surface temperature data - TS. In the step of processing, for the delimitation of land use and land cover classes, the classifier was used Supervised Support Vector Machine Classification - SVM, while in the TS analysis the band 10, consisting of thermal data from Landsat 8. The main areas of discomfort were identified inter and intra-urban thermal linked to the classes of exposed soils and built-up areas, as well as the areas of freshness associated with the presence of water bodies and streams, especially Piauí and Jurubeba, generating the letters thermal spas in 2013, 2017 and 2018. Signs of high TS are due to the removal of vegetation for expansion of agricultural and urban activities, with emphasis on building and the absence or rarefaction of areas greens for thermal comfort generation. Despite the rapid urban growth seen in Arapiraca, the heat island phenomenon is not established. Around the city the amount of exposed soil intensify TS in energy dynamics similar to built-up areas.

A Float Meter Based System for Self-Regulated Discharging and Feeding in a Laboratory Semi-CSTR for Anaerobic Digestion of Chicken Litter

HighlightsA float meter based system (FMBS) was designed for self-regulated discharging and feeding in an anaerobic semi-CSTR.The accuracy and feasibility of the FMBS were determined for anaerobic digestion of chicken litter.The FMBS had the advantages of much lower cost and better full working volume control than a digital accurate pump system (DAPS).Abstract. Given the rapidly rising costs in building lab-scale reactors, efforts are needed to examine innovative designs of reactor systems to reduce the expenses of scientific research. In this study, a float meter based system (FMBS) was designed for self-regulated discharging and feeding to operate a semi-CSTR for anaerobic digestion of chicken litter (CL) with wheat straw (WS). The FMBS functioned properly in following a feeding, reaction (stirring), settling, and discharging cycle based on the hydraulic retention time (HRT). However, clogging in the feeding or discharging lines of the reactor might occur for co-digestion of CL and WS with high TS content (C/N = 20, TS = 6%). Compared with a digital accurate pump system (DAPS), the FMBS showed the advantages of low cost ($182 << $6000) and better control of the full working volume. The longest HRT that could be achieved in this study with an exchange liquid volume of 2 L in each operating cycle was 100.7 h. In all, the FMBS design could serve as a low-cost option for designing lab-scale, semi-CSTR for anaerobic digestion as well as other reactor configurations. Keywords: Anaerobic semi-CSTR, Feeding and discharging, Float meter, Self-regulated.

Optimizing ultrasonic mist vapor deposition parameters toward facile synthesis of tungsten oxide nanofibers

Thanks to its high surface area, excellent condition for light absorption and scattering and suitable charge transport directions, nanofibrous morphology is a fascinating candidate for many important application fields. Herein as the first report, Tungsten oxide (WO2.92) thin films have been prepared via ultrasonic mist vapor deposition (UMVD) method. The effects of important growth parameters namely substrate-nozzle distance (D = 3, 5 and 8 cm), deposition time (t = 3, 6 and 18 min), substrate temperature (Ts = 130, 200 and 400 °C) and angle (θ = 0, 25 and 45°) on surface morphology of prepared thin films were investigated systematically. The analyses results revealed that Ts and θ played more determining roles affecting on tungsten oxide thin film morphology. Interestingly, very clear and obvious tungsten oxide nanofibers were deposited uniformly over the whole of substrate surface when high deposition time and angle (t = 18 min, θ = 45°) and mild substrate temperature (Ts = 200 °C) were utilized. The average diameter of grown nanofibers increased from 297 nm for θ = 0° to 429 nm for θ = 45°. No fibrous morphology was observed for the layers prepared with both low Ts = 130 and high Ts = 400 °C. Considering all of the results, a mechanism was proposed describing how the nanofibers were grown via UMVD method. obtaining fine tungsten oxide nanofibers via such a simple method is very interesting to use them as electrochromic coatings, sensors, photoelectrochemical electrodes etc.

HFE genotype and transferrin saturation in the United States

Purpose: Examine the penetrance (defined by high transferrin saturation [TS]) of C282Y and H63D in the U.S. population.Methods: 5171 participants from the Third National Health and Nutrition Examination Survey, 1992 to 1994.Results: 77.1% (95% confidence interval [CI], 2.3, 95.1) of men and 51.9% (95% CI, 0, 84.2) of women with C282Y homozygosity had high TS. The associations of H63D homozygosity with high TS were stronger in people aged 50 years or older than in younger persons. Among Mexican-Americans, simple H63D heterozygosity was associated with high TS.Conclusions: The associations between HFE genotype and high TS may vary by sex, age, and ethnic group.

Preparation of hydrogel with self-healing properties based on poly(vinyl alcohol)/corn starch/zeolite/cellulose nanocrystals for wound dressing applications

The purposes of this research are divided into three parts. Firstly, to prepare hydrogel of poly(vinyl alcohol) (PVA) and corn starch in different weight ratios between PVA and corn starch at 1:1, 2:1, 3:1, 4:1, and 5:1 by adding boric acid as crosslink agent. It revealed the ratio of PVA and corn starch at 3:1 had appropriate value for mechanical properties. Secondly, the influence of boric acid as crosslink agent and glycerol as plasticizer are investigated on properties of hydrogel. The addition of boric acid would increase the tensile strength at yield (TS), young’s modulus (YM), and water vapor transmission rate (WVTR) of PVA/corn starch films. However, by doing so would decrease elongation at break (EB) and swelling degree of hydrogel. Meanwhile, adding of glycerol lead to decrement of TS and YM but increasing EB, swelling degree, and WVTR of PVA/corn starch films. Lastly, the influence of zeolite and cellulose nanocrystals content (0.1, 0.3, and 0.5%wt) on properties of PVA/corn starch composite films are also studied. The addition of either zeolite or cellulose nanocrystals would decrease TS, YM and WVTR but increase swelling degree. Furthermore, the PVA/corn starch films incorporated with cellulose nanocrystals possesses relatively higher TS and YM than the ones with zeolite. For self-healing tests, all samples could be self-healed in wet condition.

Synthesis of fcc-Co from isostructural Co4N

This work demonstrates the synthesis of fcc-Co derived from an isostructural Co4N phase. When deposited at high substrate temperature (Ts) or thermal annealing (Ta) above 573 K, the out-diffusion of N from fcc-Co4N occurs, leaving behind a high purity fcc-Co phase. Generally, Co grows in a hcp structure, and a hcp to fcc-Co transformation can be facilitated at high temperature or pressure. The proposed route by nitridation and diffusion of N not only brings down the transition temperature but an impurity present in the form of hcp-Co can be avoided altogether as well. Oriented Co4N(111) thin films were grown using a CrN(111) template on a quartz substrate using dc magnetron sputtering. Samples were grown at different Ts or room temperature grown Co4N samples were annealed at different Ta. Analysis using x-ray diffraction, N K-edge x-ray absorption, x-ray photoelectron, and secondary ion mass spectroscopy confirmed the formation of fcc-Co4N or fcc-Co phases. Furthermore, it was found that Co–N bonding and N concentration get significantly reduced at high Ts or Ta due to exceptionally high N self-diffusion taking place in Co4N. Magnetic measurements using ex situ and in situ magneto-optical Kerr effect showed differences in saturation behavior and coercivity of Co4N and fcc-Co samples. By combining structural, electronic, and magnetization measurements, it has been observed that a high purity fcc-Co can be conveniently derived from the isostructural Co4N aided by an exceptionally high N self-diffusion in Co4N.

High microbial gas potential of Pleistocene lacustrine deposits in the central Qaidam Basin, China: An organic geochemical and petrographic assessment

Thick Pleistocene fine-grained rocks in the central Qaidam Basin, China, are regarded as the principal source rocks for microbial gas there. Here, for the first time, a detailed investigation on the organic geochemistry and petrology of this sedimentary sequence is presented. Two different, immature, lacustrine source rocks facies are present in the study area. Organic facies A samples with high TOC (4.1–25.3 wt%) and TS (1.5–3.7 wt%) contents mainly developed under a suboxic to anoxic freshwater column at the lake margins. This shallow water fluvio-lacustrine facies, accounts for only a small proportion of the whole sedimentary sequence, but has the highest petroleum generation potential. In contrast, organic facies B samples having lower TOC (0.5–1.1 wt%) and TS (0.14–1.0 wt%) contents were deposited in a more oxic, brackish-lacustrine water body. However, exceptionally, anoxic conditions were present in sediments that were sealed by algae mats.The majority of the interval is comprised of gas prone, mixed type II-III kerogen derived mainly from aquatic plants. Organic facies A is interpreted to be derived from abundant macrophytes (e.g. non-marine algae, submerged angiosperms) around the lake margin. By contrast, the organic matter in organic facies B mainly stems from saltwater algae, with some additional bacterial contribution. Terrestrial higher plants are subordinate in both organic facies. The organic carbon accumulation rate was high compared to organic matter-rich Quaternary marine sediments. Cold and dry climate conditions and high burial rates favored methanogenesis via carbonate reduction in the sediments.

The transition from dielectric-temperature stability to diffuse phase transition behavior induced by the sintering temperature for (Ba0.93La0.07)(Ti0.93Tb0.07)O3 ceramics

Nominal (Ba0.93La0.07)(Ti0.93Tb0.07)O3 ceramics (BLTT7) were prepared at different sintering temperatures of Ts = 1100–1400 °C using a mixed-oxide method. The electron paramagnetic resonance (EPR) of Tb4+ in BLTT7 acted as a probe to investigate the effect of Ts on the transition from dielectric-temperature stability to diffuse phase transition behavior. Three tetragonal BLTT7 ceramics sintered at Ts = 1100, 1200 and 1300 °C exhibited increasing dielectric-temperature stability, whereas the pseudocubic BLTT7 sintered at Ts = 1400 °C exhibited a diffuse phase transition behavior with higher permittivity and the temperature stability. A so-called core-shell structure should be responsible for the flattening of the Curie peak at Ts ≤ 1300 °C. The higher Ts (=1400 °C) led to a complete incorporation of La/Tb ions in the BaTiO3 lattice and the collapse of the core-shell structure. The transfer of Tb4+ from the shell at Ts ≤ 1300 °C to the perovskite lattice at Ts = 1400 °C was confirmed by EPR. The solid solution formation of BLTT7 sintered at different Ts is discussed.

Influence of a bark-filler on the properties of PLA biocomposites

In this study, wood plastic composites (WPC) made of poly(lactic acid) PLA and a bark-filler were manufactured. Two degrees of bark comminution (10–35 mesh and over 35 mesh) and varied content of bark (40, 50 and 60%) were investigated. The studied panels were compared with analogically manufactured HDPE boards. The manufacture of composites involved two stages: at first, WPC granules with the appropriate formulation were produced using the extruder (temperatures in individual extruder sections were 170–180 °C) and crushing using a hammer mill after cooling the extruded composite; secondly, the obtained granulate was used to produce boards with nominal dimensions of 300 × 300 × 2.5 mm3 by flat pressing in a mold, using a single daylight press at a temperature 200 °C. The study proved that comminuted bark can be applied as a filler in PLA composites. However, an increase in bark content decreased mechanical properties (MOR, MOE) and deteriorated humidity resistance (high TS and WA) of the panels. Along with the increase in bark content, an increase in the contact angle of the composite surfaces and a decrease in the total surface energy were noted. It was also found that PLA composites have higher strength parameters and lower moisture resistance compared to HDPE composites with the same bark content.Graphical abstract

A study on Australian sorghum grain fermentation performance and the changes in Zaopei major composition during solid-state fermentation

Sorghum is an essential raw material traditionally used for baijiu production by solid-state fermentation (SSF). China imports Australian sorghum for animal feed and for baijiu production. Determination of the sorghum characteristics specific for baijiu production will enable target breeding for such purpose. This study used five Australian grain sorghum varieties and one Chinese variety for baijiu solid-state fermentation in order to determine the grain sorghum properties most suitable for ethanol production. Ethanol content was highly correlated with the grain total starch content (TS) (r = 0.675, p < 0.05), amylopectin (AP) content (r = 0.590, p < 0.05), C/N ratio (r = 0.837, p < 0.001) and crude protein content (r = −0.813, p < 0.01). This study concluded that the grain sorghum variety that produced high ethanol content, had higher TS, AP and C/N ratio but lower crude protein content. Changes in grain composition during fermentation was also studied. SSF involved the consumption of mainly amylopectin instead of amylose and non-resistant starch instead of resistant starch irrespective of sorghum variety. All fermented samples were found to have increased protein content.

Effects of Tensile Testing Temperature on Mechanical Properties and Deformation Behavior in Medium Mn Steels

In single-phase austenitic steels, the optimum deformation temperature in the tensile test to obtain high tensile strength-elongation balance (TS×El) and work hardening rate (dσ/dε) depends on control of the stability of austenite. In order to clarify the effects of the deformation temperature in complex phase steels containing austenite, in this study, the effects of the tensile testing temperature on mechanical properties and deformation behavior were investigated in detail using steel A and steel B with a chemical composition of 0.15C-0.5Si-5.0Mn (wt%). Steels A and B consisted of ferrite and retained austenite, but contained different volume fractions of retained austenite, namely, 29 % and 17 % as a result of annealing at 660 °C and 620 °C for 2 h, respectively. The stability of the retained austenite of steel B was higher than that of steel A. In steel A, TS×El and dσ/dε achieved their maximum values at 20 °C, decreased from 20 to 100 °C, and then remained almost unchanged at more than 150 °C. On the other hand, in steel B, TS×El and dσ/dε achieved their maximum values at -40 °C, decreased from -40 to 50 °C and remained almost unchanged at more than 100 °C. These results can be explained by the stability of retained austenite and the transformation rate from retained austenite to martensite. It should be noted that control of the stability of retained austenite and the transformation rate from retained austenite to martensite led to an adjustment of the optimum deformation temperature to achieve the high TS×El and dσ/dε in medium Mn steels, in the same manner as in single-phase austenitic steels.

Structural and optical properties of quasi-2D GaTe layers grown by molecular beam epitaxy on GaAs (001) substrates

Quasi-two-dimensional GaTe layers were grown by molecular beam epitaxy on GaAs (001) substrates at Ts = 450–520°C. The effect of the growth temperature on the GaTe surface morphology has been studied by scanning electron microscopy. It is shown that GaTe layer grown at high Ts = 520°C exhibits pronounced surface relief anisotropy. This sample demonstrates also near band-edge photoluminescence (PL) at T = 11K with the peak energy of ∼1.72 eV, which can be associated with the emission of excitons bound at the acceptor. The nature of 1.45 eV and 1.57 eV peaks appearing in the PL spectra is also discussed in detail.

Comparison of high temperature growth versus post-deposition in situ annealing in attaining very low Gilbert damping in sputtered Co2FeAl Heusler alloy films

In this work, a detail study on the effectiveness of high substrate temperature (TS) during deposition versus in situ annealing of the films at high temperature (TA) after sputtering at room-temperature is compared with an objective to obtain Heusler alloy thin films of Co2FeAl (CFA) having optimally low αint (with an upper bound of 1.75 × 10-3) and 12–17% smaller MS by employing ion beam sputtering technique and Si(100) as substrates for current induced magnetization switching application. In each of the two series of CFA films, prepared with different choice of TS and TA (lying in 300–773 K range) were explored for optimally tailoring their structural, static and dynamic magnetization properties. Structural study revealed that although all the CFA films were polycrystalline but the post-deposition annealed films were structurally optimal with higher density (6.36 ± 0.09 g/cm3) and lower interface roughness (0.48 ± 0.03 nm) compared to the CFA films grown at high TS (6.23 ± 0.06 g/cm3, 0.61 ± 0.01 nm). In plane field-angle dependent longitudinal magneto optical Kerr effect (L-MOKE) study revealed the existence of a coupling between the weak uniaxial and biaxial magnetic anisotropies present in these films, attributed to the employed deposition geometry. Ferromagnetic resonance (FMR) spectroscopy measurements, performed in both the geometries - in-plane as well as out of plane, revealed a lowest value of 1.19 (±0.08) × 10-3 of αint in the film post-annealed at 773 K. In addition, the observed non-linear relation between the αint and the dynamical ‘g’-factor suggests that the contribution of spin orbit interaction to the damping is far less compared to the damping contribution from the DOS present near the Fermi level. It is remarkable to note that the as-grown CFA films sputtered at room temperature exhibited a record lowest value of 1.73 (±0.09) × 10-3 of αint. Attainment of such small value of Gilbert damping and having moderate magnetization in high spin polarized Co2FeAl Heusler films sputtered on the Si (100) substrate opens up their great application potential in future spintronics devices.

The effects of active double-layered furcellaran/gelatin hydrolysate film system with Ala-Tyr peptide on fresh Atlantic mackerel stored at −18 °C

This is the first time that active double-layered furcellaran/gelatin hydrolysate films containing Ala-Tyr peptide were developed and characterised for their properties. Afterwards, films were used on Atlantic mackerel stored at −18 °C for 4 months and samples were analysed for changes in their microbiological quality, TVB-N, biogenic amine content, fatty acid composition and TBARS. Active films had higher TS (13.4 MPa) and lower WS (62.8%). The films showed no DPPH radical scavenging properties but high FRAP (6.6 mMol Trolox/mg). No significant effects on the oxidation of fish samples were observed with TBARS increasing from 12.04 to 22.50 mg/kg. Freezing successfully inhibited the growth of microorganisms and no differences in microbiological growth or biogenic amine formation were observed. However, the application of films inhibited the formation of TVB-N. Antimicrobiological properties of the film should be further investigated during storage of perishable food products at temperatures above 0 °C.

The effects of sex and aging on selected plasma biochemistry analytes in zoo-kept American flamingos (Phoenicopterus ruber)

American flamingos (Phoenicopterus ruber) are commonly kept in zoological collections and are important in research, conservation awareness, and education. Hematology and biochemistry parameters are reported to change with age in many long-lived species. A retrospective analysis of recorded data (147 samples of PCV/TS and plasma biochemistry) from n = 16 (F = 7, M = 9) zoo-kept flamingos (1–16 years) was performed. Blood samples were collected as part of routine annual health evaluation over the course of 11 years. The effect of aging and sex on biochemical analytes in individuals over time was assessed. Most analytes did not differ between sexes. Males had higher TS, and lower sodium, chloride, and ALT concentrations when controlling for age. The only variable with a significant sex × age interaction was ALP, which only changed with age in females. Most analytes did not differ with age. PCV, UN, and Na:K ratio increased, while potassium, ALP, and uric acid concentrations decreased with each year of life. While aging influenced select biomarkers in the current study, the clinical significance has yet to be determined, and further studies including a larger age range are recommended.

Occurrence of Sharp Hydrogen Effusion Peaks of Hydrogenated Amorphous Silicon Film and Its Connection to Void Structures

The amount of hydrogen released from plasma‐enhanced chemical vapor (PECVD) deposited hydrogenated amorphous silicon (a‐Si:H) layers is determined by gas effusion measurements. A sharp peak (SP) is observed in the effusion spectra of samples with substrate temperature T S ≥ 200 °C. Light microscopic images indicate the formation of bubbles after deposition for all samples and film deterioration after effusion measurement in correlation with the presence of the hydrogen SPs. Change in substrate temperature varies with the microstructure of the film, the hydrogen concentration, and the density. A low T S leads to a porous structure with large number of interface bubbles, and therefore no hydrogen‐induced SP appears during hydrogen effusion. Whereas high T S causes a compact a‐Si:H film in which the hydrogen effusion is limited by the longer diffusion, while the number of interface bubbles decreases. The storage of near substrate hydrogen in the bubbles in compact material leads to a local explosion by increase in excessive pressure. The difference between the low temperature peak and the position of the SP in the effusion spectra indicates the time required to fill the interface bubbles with hydrogen, which decreases with increasing film density, suggesting that the volume of the interface bubble decreases.

Physical properties of CuIn0.7Ga0.3Se2 ingot and thin films prepared by one-step rf-magnetron sputtering from single-target material

Nowadays, large area CuIn1-xGaxSe2 (CIGS) thin film fabrication by one-step radio-frequency magnetron sputtering is still facing difficulties and challenges in uniformity of composition and structure. This study illustrates how we can prepare polycrystalline thin layers of CuIn0.7Ga0.3Se2 on glass and on F-doped SnO2/SLG substrates using single quaternary target. It was found that using direct reaction of stoichiometric proportions of pure elements, we can make high quality CIGS powder to prepare sputtering target. X-ray diffraction study of CIGS powder revealed all possible orientations for the CIGS material. Compositional analysis of the obtained CIGS crystal surface was also investigated. To investigate the defect chemistry, Cathodoluminescence (CL) measurements at different temperatures were carried out. The structural, compositional, morphological, and electrical properties of the as-deposited films were systematically investigated by XRD, SEM, AFM, and four-point probe method. By adjusting the processing parameters at high substrate temperature TS = 300 °C, a CIGS thin films with a preferential orientation along (112) direction which exhibited single chalcopyrite phase were obtained. The optical transmission showed energy gap value up to 1.19 eV and rather sharp absorption fronts which is suitable for high efficient solar cells.