Effect Of Low-temperature Annealing Research Articles

Improved electrical performance for SiO2/β-Ga2O3 (001) MIS capacitor by post-deposition annealing

In this study, we have fabricated a high-performance SiO2/β-Ga2O3 (001) MIS capacitor and investigated the effect of low-temperature post-deposition annealing (PDA) on its electrical properties. The SiO2/β-Ga2O3 (001) MIS capacitor exhibits improved gate leakage current and breakdown electrical field after the PDA treatment. The high-frequency capacitance-voltage hysteresis curves reveal that the fixed charge density, as well as the fast and deep near-interfacial trapped charge densities, decreases with the PDA process. We achieved an interfacial trapped charge density as low as 1.6 × 1011 cm−2 eV−1 at an energy of 0.6 eV below the conduction band of β-Ga2O3 (001) through 400 °C annealing.

Effect of Low-temperature Annealing on Mechanical Properties of Warm-rolled High Silicon Steel Produced by Twin-roll Strip Casting

Effect of Low-temperature Annealing on Mechanical Properties of Warm-rolled High Silicon Steel Produced by Twin-roll Strip Casting

Effect of surfactant-assisted low-temperature annealing on the refinement of particle size and enhancement of magnetic properties of SrFe12O19 ferrite

The fabrication of SrFe12O19 ferrite powders with good magnetic properties is a key process in the industrial production of permanent magnets. Remanence and coercivity of the powders was seriously decreased due to the generation of surface lattice defects produced during the crushing of pre-sintered ferrite powders. And the traditionally applied high-temperature annealing above 800 °C can only partially restore the magnetic properties. In this work, the effects of types, adding mode and contents of surfactant (hexadecyl trimethyl ammonium bromide, triethanolamine) on the magnetic properties of crushed powders of the pre-sintered SrFe12O19 ferrite under a low-temperature annealing of 400 °C process were systematically explored. The results showed that surfactants are beneficial to restore or even enhance the magnetic properties of the crushed powders compared with the pre-sintered ferrite due to the refinement of the particles and repairing the surface defects. The surfactant-assisted low-temperature annealing process proposed in this work will promote the commercial production of high performance ferrite powders and ferrite magnets, which can also effectively reduce the production energy consumption.

Effect of low-temperature annealing on electric resistivity and mechanical anisotropy of Al-Si binary alloy fabricated by laser-powder bed fusion

Al-12mass%Si binary alloy was fabricated by laser-powder bed fusion (L-PBF). The effect of low temperature annealing (LTA) less than 573 K on electrical and mechanical properties, microstructure, and residual stress of L-PBF Al-12mass%Si was investigated. Due to LTA, electrical resistivity at 77 K and 293 K changed from 34 nΩm down to 10 nΩm and from 68 nΩm down to 45 nΩm, respectively. The lattice constant of α-Al phase increased around 0.0005 nm by LTA according to X-ray diffraction. The change was associated with the decrease in the concentration of solid-solution Si of around 3.4 mass% by electrical resistivity measurement and 3 mass% by X-ray diffraction, when the annealing temperature was 473 K. Whereas, Vickers hardness increases around 145 HV compared with that for the as-built value of 141 HV, and then, decreases down to 126 HV and saturates. TEM/EDS observations confirmed the precipitation of fine Si within the α-Al phase. The decrease in annealing temperature increases the time to reach the Vickers hardness peak. 0.2% proof stress obtained by compression tests shows anisotropy, which can be attributed to the anisotropy on residual stress, which still exists after LTA.

Effect of low-temperature annealing in air on the defect structure of oxide nanoparticles

It has been found that low-temperature annealing in air changes the defect structure of YSZ10 oxide nanoparticles synthesized by means of the laser evaporation of a ceramic target. The study is carried out with the use of deuterium probes. At a temperature of 350 ℃, with increasing annealing time, a monotonic decrease in the concentration of oxygen vacancies near the surface of nanoparticles is observed. This dependence is extreme at 200 ℃; at its first stage, the concentration of vacancies in the surface atomic layer of nanoparticles increases with time. An approach is proposed for the synthesis of nanoparticles with severe oxygen deficiency near the surface of oxide

Effects of low-temperature annealing on net doping profile of Mg-ion-implanted GaN studied by MOS capacitance–voltage measurement

Effects of long-term low-temperature cap annealing on the net doping profile of Mg-ion-implanted GaN were studied using MOS structures before activation annealing. Mg ions were lightly implanted into n-type GaN to maintain the n-type conduction. Various cap-layer materials, i.e. Al2O3, SiN, SiO2 and capless, for low-temperature annealing were examined. Doping profiles were derived from capacitance–voltage (C–V) curves. Before 600 °C annealing, negatively charged defects were distributed on the shallower side of the detection depth range, whereas positively charged defects existed on the deeper side. Upon 600 °C annealing, however, the doping profile changed toward a flat shape regardless of the cap-layer material used during annealing. The observed profile change was likely caused by the diffusion of defects. Detailed analyses of C–V characteristics showed that the highly likely cause of the observed phenomena is the diffusion of Ga and N interstitials.

Effect of Low-Temperature Annealing on the Bending Properties of C19400 Copper Alloy Strips

Effect of Low-Temperature Annealing on the Bending Properties of C19400 Copper Alloy Strips

Effect of low-temperature annealing on microstructure and mechanical properties of Ti6Al4V produced by laser shock peening

In this study, a combination of laser shock peening (LSP) and low-temperature annealing (LTA) was used to modulate the microstructures of Ti6Al4V, which can achieve an optimal combination of strength and plasticity. Microstructure observations showed that after LSP treatment, serious plastic deformation and grain refinement occurred. This resulted in the formation of non-equilibrium grain boundaries (GBs) composed of dislocations, twins, and martensite transformation. After LTA treatment, the dislocation density decreased as it rearranged, resulting in GB relaxation. The GB state can change from non-equilibrium to equilibrium. Additionally, LTA treatment can increase the activation energy and facilitate element diffusion from high to low concentration. The decrease in dislocation density and element diffusion results in GB with low excess energy, increasing the stability of the microstructural. The LSP composite LTA treatment showed a high tensile strength of 994 MPa and an excellent elongation of 17.4% compared to the untreated specimen. Excellent microstructure stability and mechanical properties are achieved in Ti6Al4V after combined post-treatment of LSP and LTA.

Effect of low-temperature annealing on electrical resistivity and mechanical properties of laser-powder bed fused AlSi10Mg alloy

The AlSi10Mg sample was additive-manufactured using laser powder bed fusion (L-PBF), and subsequent low-temperature annealing (LTA) at 413K or 473 K was applied. Vickers hardness tests show the peak at around 160 HV by 473 K annealing and around 145 HV by 413 K annealing. The flow stress of tensile and compression deformations are also affected by LTA, and peak aging condition gives the highest 0.2% proof stress. 0.2% proof stress obtained by tensile tests is around 270 MPa, whereas that obtained by compression tests is between 326 MPa and 386 MPa. Electrical resistivity at 293 K changes from approximately 80 nΩm down to around 60 nΩm, whereas that at 77 K changes from around 40 nΩm down to around 20 nΩm. The estimated concentration of solute Si in the as-built specimen is between 2.5 mass% and 2.9 mass%, corresponding to the previous results using energy-dispersive X-ray spectroscopy. The lattice constant obtained from XRD increased from 0.4043 nm up to 0.4048 nm by LTA. Both electrical resistivity and XRD measurement indicate a decrease in the concentration of solute atoms. Microstructure observations revealed numerous nano-sized precipitates of Si phase with a plate-like or granular morphologies in α-Al grains due to LTA.

Making pyrocatalytic oxidation of micropollutants real – Revealing the activity-enhancing effects of low-temperature annealing on BaTiO3

Among the numerous techniques for water remediation, disinfection, and hydrogen generation, only pyrocatalysis has the potential to harvest and utilize energy from the environment as well as industrial processes in the form of temperature differences. In this work, our purpose was to reach a drastic improvement of the pyrocatalytic activity of BaTiO3 powders (BT) by decreasing the particle size in combination with catalyst annealing at temperatures between RT and 1000 °C. In the end, we reached our goal for a BT with a nominal particle diameter of 50 nm via low-temperature annealing at temperatures of only 300 °C. The activity boost was demonstrated for the dichlorofluorescein (DCF) oxidation assay (+585 %), the degradation of 4-hexylresorcinol (+1150 %) and, for the first time, the successful degradation of the micropollutant bisphenol A (+460 %). Using material characterization in combination with in-depth literature comparisons, we elucidated the underlying mechanism. It deviates strongly from our original assumptions as it includes the generation of oxygen vacancies. Based on our findings, several strategies for further improving pyrocatalysis were derived to enable an effective catalyst design. This will help pyrocatalysis to take the next step on its way towards an energy-efficient technique for water remediation.

Time-resolved terahertz spectroscopy for probing the effects of low-temperature annealing on CsPbBr3 evaporated thin-films

The fine-tuning of the growth conditions and post-deposition treatments is of fundamental importance to improve the efficiency of photovoltaic devices based on all-inorganic metal halide perovskites like CsPbBr3. In this work, we used time-resolved terahertz spectroscopy (TRTS) in combination with optical characterization techniques, x-ray diffraction (XRD), and scanning electron microscopy, to probe the different properties induced by a low-temperature (180 °C) annealing treatment on evaporated CsPbBr3 thin-films. We observed a faster build-up and relaxation dynamics in the annealed sample, accompanied by a remarkable decrease of the photoluminescence intensity and minor changes in the photoconductivity and XRD measurements as compared to the as-deposited sample. We estimated for both the samples a mobility of cm2 V−1 s−1. Our results suggest that the lattice reorganization induced by low-temperature annealing of evaporated CsPbBr3 could lead to a different charge carrier-phonon coupling and to an increased contribution of non-radiative recombination channels. We found that TRTS can be effectively used to follow the changes induced by post-deposition thermal annealing of CsPbBr3.

Effect of low-temperature annealing on Bi-poor Cs2AgBiBr6 single crystals

All-inorganic double perovskite Cs2AgBiBr6 has attracted increasing research interest due to its great potential for optoelectronic applications. To date, most studies focus on the room-temperature characteristics of as-grown Cs2AgBiBr6 single crystals. In this work, we investigated the effect of low-temperature annealing on the physical properties of Cs2AgBiBr6 single crystals. The studied Cs2AgBiBr6 single crystal was grown using a Bi-poor precursor and has a bandgap of 2.12 eV, showing superior elastic properties with Young’s modulus at 32 GPa and hardness at 1 GPa. When the annealing temperature increased from 25 °C to 80 °C, the resistivity of the as-fabricated Bi-poor Cs2AgBiBr6 crystal decreased from 8.07 × 109 Ω cm to 5.86 × 107 Ω cm. Interestingly, the room-temperature resistivity of the annealed Cs2AgBiBr6 increased nearly 3 times when compared to the original value before the annealing. After the annealing, the Cs2AgBiBr6 crystal still holds a strong response to radiation sources. The temporal response of the Cs2AgBiBr6 crystal under the 568-nm LED illumination also indicated that the rising time and the decaying time are much shorter than the initial values before the annealing. These results demonstrate a robust thermal and air stability of Bi-poor Cs2AgBiBr6 single crystal. An effective annealing strategy could play an important role in tuning the fast decay- and rise-time characteristics of Cs2AgBiBr6 single crystals.

The Effect of Low-Temperature Annealing on the Magnetic Characteristics of an Amorphous Magnetically Soft Cobalt Based Alloy

The Effect of Low-Temperature Annealing on the Magnetic Characteristics of an Amorphous Magnetically Soft Cobalt Based Alloy

Low-Temperature Annealing of CdTe Detectors With Evaporated Gold Contacts and Its Effect on Detector Performance

Cadmium telluride (CdTe) detectors are usually subjected to elevated temperatures during postprocessing and bonding them to readout electronics while fabricating imaging arrays. We studied the effects of low-temperature and short duration rapid thermal annealing of CdTe bulk as well as CdTe epitaxial-layer-based detectors with evaporated gold contacts. The detectors were annealed in the temperature range of 100 °C–300 °C, and its effect on the detector dark current, gamma detection property, and response stability was studied. For the bulk-detectors, the detector dark current decreased and gamma detection properties as well as the performance stability improved after annealing. However, such improvements were moderate for epitaxial-layer-based detectors. The study of the metal–semiconductor interface of annealed detectors revealed that diffused gold, elemental oxygen, and tellurium oxide existed and extended deep inside the bulk portion in epitaxial detectors; however, they were confined in the surface regions only in bulk-detectors, which likely be the causes of observed results in these two types of detectors.

Annealing effect on thermoelectric characteristics of Spin-coated Cu2Se nanoparticle thin films

In this study, we fabricated a spin-coated Cu2Se nanoparticle (NP) thin film on a plastic substrate and investigated the effects of low-temperature annealing on its thermoelectric characteristics. After thermal annealing at 150 ℃ for 10 min in vacuum, the electrical conductivity of the Cu2Se NP thin film was dramatically enhanced from 1.05 × 102 to 2.09 × 104 S/m, whereas its thermal conductivity slightly increased from 0.11 to 0.50 W/m∙K. The power factor and the figure of merit of the annealed Cu2Se NP thin films at room temperature in air was 25.6 μW/m∙K2 and 1.54 × 10−2, respectively.

Effect of low-temperature rapid annealing on structural and electrical properties of electroless platinum contacts on CdZnTe detectors

In this work, platinum (Pt) electrodes were deposited on CdZnTe wafers by electroless H2PtCl4 solution and subsequently annealed at different temperature from 323 K to 473 K. Focused ion beam (FIB) imaging, transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), current-voltage (I–V) analysis and energy spectra under 241Am irradiation were adopted to investigate the effect of low-temperature rapid annealing on interface structure, electrical and carrier transport properties of Pt/CdZnTe samples. Single-crystal PtTe layer with [100] orientation and thickness of 20 nm was found in the interface between electroless Pt and CdZnTe wafer. The leakage current of the Pt/CdZnTe detectors at 200 V decreased from 212 nA cm−2 to 101 nA cm−2 after low-temperature rapid annealing, due to a decrease of voltage drop across the PtTe interface layer. The energy spectra and carrier transport performance of Pt/CdZnTe detectors suggested that the optimal annealing temperature was 423 K. The energy spectra of Pt/CdZnTe detector under 241Am showed that the FWHM was improved from 23.3% to 14.4%, while the full charge collection and mobility lifetime product of electrons increasing from 611 to 625 and 3.17 × 10−3 to 3.76 × 10−3 cm2 V−1 s−1, respectively.

Effect of low-temperature annealing on two-different severely cold-rolled steels

The present work is on the effect of low-temperature annealing (or tempering) treatment of two severely cold rolled ultra-high-strength steels. Cold rolling of hot rolled steels significantly enhanced the dislocation density in martensitic and bainitic steels, leading to increase in the YS and UTS of both the steels. Further, these hot rolled high strength steels were cold rolled to about 70% reduction. It is proposed that the cold rolling process might have improved the stability of retained austenite within a range of 15 – 20 mJm–2 through a dynamic interaction process between retained austenite and dislocations during each rolling pass. While the initial passes were associated with the mechanical stability of retained austenite in the steels, the final stage was influenced by the rolling strain and heat generated during cold rolling process. The carbon partitioning at the dislocation sites too had a similar effect on increasing YS and UTS during relatively low-temperature annealing in both the steels. There was a difference in the YS values of two highly deformed steels in post annealing condition, which was due to the intrinsic hardness of the phases present in those steels, nevertheless, both the martensitic and bainitic steels had similar work hardening rates at each annealing temperature. It is also proposed that activities like carbon-dislocation pinning, recovery, and precipitation during annealing in any highly deformed steel may be governed through a similar mechanism, which can work independently irrespective of the phases present in the microstructure.

Effect of Boron Content and Low-Temperature Annealing on the Structure State and Tribological Properties of Electrodeposited Ni-B Coatings

Effect of Boron Content and Low-Temperature Annealing on the Structure State and Tribological Properties of Electrodeposited Ni-B Coatings

Effect of Low Temperature Annealing on Anatase TiO2 Layer as Photoanode for Dye-Sensitized Solar Cell

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.

Effect of low-temperature annealing on the superelastic response and electrochemical corrosion behaviour of equi-atomic Ni-Ti alloy

ABSTRACT Nickel–Titanium (Ni–Ti) alloys have exemplary properties such as good thermo-mechanical response and biocompatibility. Hence, they are one of the prime materials of interest in today’s context for the fabrication of advanced biomedical devices. Such properties can be exemplified with certain techniques such as heat-treatment techniques. However, peer-reviewed literature for the same appears to be inadequate to efficiently quantify the effect of such techniques on the overall performance of such materials. Therefore, the present study focuses on analysing the effect of low-temperature heat treatment on the superelastic behaviour and corrosion resistance of titanium-rich Ni–Ti alloys. The superelastic behaviour has been evaluated for different strains. Meanwhile, the Tafel extrapolation method is incorporated to assess the electrochemical corrosion of these materials. It is noticed that the low-temperature heat treatment has marginal effects on the superelastic behaviour of the alloy. The Ni–Ti alloy annealed at 450°C at 6% predetermined strain rate showed the best enhancement in the superelastic behaviour and the corrosion resistance increased upto treatment temperatures of 350°C. Therefore, the most optimum temperature of annealing is found to be 350°C, resulting in about 35.72% improvement in the corrosion resistance of the alloy when compared to their untreated counterparts.