Increase Of Annealing Time Research Articles

Fabrication and Characterization of Aluminum-Doped Nickel Oxide Thin Films for Optoelectronic Applications using the SILAR Method

Study’s Excerpt The effect of varying annealing times on 10% Aluminum-doped Nickel Oxide (ANO) thin films, deposited via the SILAR technique is presented. SEM and RBS analyses were used for detailed correlation between annealing time and the film's microstructural improvements. ANO thin films could be used for advanced technological applications. Full Abstract The effect of varying the annealing time of %10 aluminium-doped Nickel Oxide thin film was studied to understand the possible effect on the optical, structural, and electrical properties of %10 aluminium-doped Nickel Oxide (ANO) for possible application. The thin films were deposited on glass substrates using the successive ionic layer adsorption reaction (SILAR) deposition technique. The samples formed were annealed at 3000C, and the annealing time varied at 1.35 hrs., 1.45 hrs., 1.55 hrs., and 2 hrs, respectively. The deposited films were characterized to obtain the optical, electrical, and structural characteristics and the compositional constituent of the film using the double beam photo spectrometer, Four-Point Probe, Scanned electron Microscope, Energy Dispersion Spectroscopy, and X-ray Diffractometer. The films were observed to have low absorbance in the range of 0.1 to 0.01 and high % transmittance within the range of 80% - 98% in the visible region of the spectrum. The reflectance of the film was observed to decrease with an increase in annealing time in the range of 10% - 2.5%, all in the visible region of the spectrum. The crystallite size of the deposited films decreased with increased annealing time with the structural formation of simple cubic phase NiO thin film. SEM micrograph of the thin films reveals that an increase in annealing time improved the crystallinity of the films with the grain size evenly distributed. The EDS result of the deposited films revealed the presence of nickel, aluminum and Oxygen as the major constituent of the deposited films. The Ruther Ford Backscattering (RBS) analysis of the thickness of the films shows an increase in the thickness with an increase in annealing time. Clearer compositions of the films were also seen from the RBS analysis. Their electrical properties revealed that the films formed had low electrical resistivity and high conductivity, so they could be useful in making optoelectronics devices and corrosion resistance.

Fabrication and characterization of NiO nanoparticles deposited via reactive DC magnetron sputtering technique

Nickel oxide (NiO) nanostructure was successfully prepared via reactive DC magnetron sputtering on the soda-lima glass substrate, which can be used for various applications. Xray diffraction (XRD) investigations were used to evaluate NiO with two annealing durations. The results revealed that the deposited films had a cubic structure and polycrystalline nanoparticles. A significant polycrystalline structure could be seen in the sputtered films as a diffraction peak oriented toward NiO (200). Field-emission Scanning Electron Microscopy (FE-SEM) analysis identified the surface morphology of NiO nanoparticles prepared at two different annealing times with the two average sizes (24 and 32 nm) respectively. The samples' roughness was assessed using atomic force microscopy (AFM). Increased annealing time was shown to result in a decrease in grain size. The energy band gap (Eg) expanded with increasing annealing time, according to UV-visible spectroscopy (UV-Vis). FTIR spectroscopy was used to determine the functional groups of NiO nanoparticles and their bonding nature. The results indicate that optical characterizations are more sensitive to the annealing period.

Fabrication and characterization of NiO nanoparticles deposited via reactive DC magnetron sputtering technique

Nickel oxide (NiO) nanostructure was successfully prepared via reactive DC magnetron sputtering on the soda-lima glass substrate, which can be used for various applications. Xray diffraction (XRD) investigations were used to evaluate NiO with two annealing durations. The results revealed that the deposited films had a cubic structure and polycrystalline nanoparticles. A significant polycrystalline structure could be seen in the sputtered films as a diffraction peak oriented toward NiO (200). Field-emission Scanning Electron Microscopy (FE-SEM) analysis identified the surface morphology of NiO nanoparticles prepared at two different annealing times with the two average sizes (24 and 32 nm) respectively. The samples' roughness was assessed using atomic force microscopy (AFM). Increased annealing time was shown to result in a decrease in grain size. The energy band gap (Eg) expanded with increasing annealing time, according to UV-visible spectroscopy (UV-Vis). FTIR spectroscopy was used to determine the functional groups of NiO nanoparticles and their bonding nature. The results indicate that optical characterizations are more sensitive to the annealing period.

Effects of diamond/Al interface structure evolution on interfacial thermal conductance during the carbonization of the Cr interlayer

The correlation between the interface structure evolution and the interfacial thermal conductance (ITC) in diamond particles reinforced Al matrix (diamond/Al) composites has been largely unclear. Herein, diamond/Cr/Al nanolayered structures with the interlayers in different carbonization stages were prepared via magnetron sputtering and annealing treatment to simulate the interfaces in diamond/Al composites. As the annealing time increases, the formed Cr3C2 phase progressively grows from discrete particles to a continuous layer at the diamond/Cr interface, during which the thickness of the carbide layer gradually increases. The formation of Cr3C2 phase improves the interface bonding and provides a more convenient channel for the heat exchange of hot carriers between the interfaces. Accordingly, the ITCs of the samples gradually increases with the annealing time and reaches the maximum value of 436.66 MW/(m2·K) at 120 min due to the formation of a thin and continues Cr3C2 layer. However, considering high interfacial thermal resistance was introduced at the interface when the Cr3C2 interlayer is too thick, the ITC of the sample decreased to 321 MW/(m2·K) as the annealing time extended to 240 min. In addition, Al8Cr5 phase is generated at the Al/Cr interface, but its impact on the ITC of the samples is negligible due to the small amount.

Revealing the effect of annealing at Tg on the crystal growth in Au49Ag5.5Pd2.3Cu26.9Si16.3 metallic glass via nanocalorimetry

In this study, Au49Ag5.5Pd2.3Cu26.9Si16.3 metallic glass is annealed at Tg and its impact on crystal growth is demonstrated with nanocalorimetry. With annealing following the rapid quenching, an amorphous phase free of nuclei, a relaxed amorphous phase, an amorphous phase with nuclei, and an amorphous phase with crystals are sequentially produced. With the reheating at rates ranging from 100 to 50,000 K/s, these four stages are quantitatively distinguished. Additionally, crystal growth behaviors of these four stages are demonstrated by the Kissinger and Mauro-Yue-Ellison-Gupta-Allan model. For the quenched and relaxed amorphous phases, the apparent crystallization activation energy (Ea) decreases with increasing heating rate, with a noticeable upward deviation at ultrahigh heating rates. When nuclei and crystals form in the amorphous phase, Ea keeps decreasing with the heating rate. As the annealing time increases, the maximum growth rate (umax) exhibits a monotonic increase while the temperature corresponding to umax displays a maximum.

Influence of post-deformation annealing conditions on microstructures and mechanical properties of hypereutectoid steel wires during cold drawing

Abstract This investigation delves into the complex influences of annealing conditions post-deformation, such as duration and heat levels, upon the microstructure, as well as the mechanical properties of hypereutectoid steel wires subjected to cold drawing. XRD and VSM analyses confirmed that higher annealing temperatures precipitated a notable increase in cementite volume, concurrently inducing the spheroidization of cementite lamellae. This transformation was evidenced by the expansion of cementite volume and the transition of cementite layers into a spherical morphology as the annealing temperature increased. The evolution of tensile strength in response to varying annealing temperatures and time revealed two distinct patterns. Initially, at lower annealing temperatures ranging between 200°C and 300°C, tensile strength exhibited an upward trajectory with increasing annealing time. This phenomenon can be attributed to age-hardening mechanisms, notably associated with solution hardening. As annealing time increases, the decomposition of cementite releases additional carbon atoms into the ferrite matrix. These carbon atoms act as effective barriers, hindering dislocation movement within the structure and consequently contributing to increased tensile strength. However, this increase in carbon content within the ferrite matrix also elevated the susceptibility to delamination phenomena. Conversely, at higher annealing temperatures of 400°C and 500°C, a contrasting trend was observed, characterized by a consistent decline in tensile strength post-annealing. This decline could be attributed to the phenomenon of aging softening, wherein the process of spheroidization and re-precipitation of cementite resulted in a reduction of dissolved carbon atoms within the ferrite matrix. Consequently, this led to a decline in tensile strength as well as a reduced incidence of delamination. In summary, the study explored how different annealing conditions affect the structure as well as the strength of hypereutectoid steel wires, revealing detailed mechanisms behind these changes.

Optical characterization and thermal analysis of rare earth-doped PbO-GeO2-Ga2O3 glasses embedded with gold nanoparticles

This study investigated the optical properties of PbO-GeO2-Ga2O3 glasses doped with Er3+ and Yb3+ rare earth ions, deposited with gold nanoparticles and annealed at different times (1 h, 12 h, 28 h, and 52 h). By varying the annealing times, we can understand how these thermal processes influence the position of the energy bands, which in turn affects the material’s optical properties such as the energy gap and Urbach energy. The study found that the sample annealed for 52 h had the lowest Eg value and the highest Eu value, indicating significant structural changes due to prolonged thermal treatment. The study aimed to determine the energy gap (Eg) and Urbach energy (EU), Judd-Ofelt parameters (Ω2, Ω4, Ω6), oscillator strength (fexp and fcal), and root mean square (RMS) deviation. Additionally, the study reports on the linear absorption and heat transfer results, which were used to evaluate temperature changes during Z-scan experiments. The data obtained indicate that the sample subjected to 52-hour annealing has the smallest Eg value, suggesting that intense thermal processes and crystallisation affect the positions of the material’s energy bands, increasing its ability to absorb light. Consequently, the EU value for this sample is the highest at 0.312 eV, decreasing to 0.203 eV for the sample annealed for 1 h. This indicates that longer annealing times result in more significant structural changes in the glass matrix, thereby modifying its optical properties. The analysis of the obtained results, leads to the conclusion that the lowest values of both experimental (fexp) and calculated (fcal) oscillator strength occur at 546 nm and 811 nm, indicating the potential energy properties of the 4S3∕2 and 4I9∕2 levels in the atomic structure. It was observed that the J-O parameters did not exhibit significant changes with increased annealing time, suggesting that short-term thermal processes may be sufficient to achieve a stable energy configuration. This finding is of significant practical importance, as it indicates that the material can maintain its optical properties even with shorter annealing times, thereby enhancing the efficiency of the production process.

Microstructure and mechanical properties evolution of 310S and GH3536 in hydrogen metallurgy service

The evolution of microstructure and mechanical properties of 310S austenitic stainless steel and GH3536 nickel-based alloy in hydrogen metallurgy service condition is investigated by conducting heat treatment under high temperature and hydrogen atmosphere. As the annealing time increases at 750 °C, carbide precipitate phases of the σ and μ brittle phases appear in the materials. At 900 °C, the dissolution of carbides induces the dispersion of brittle phases, while the hydrogen content reaching its peak. These brittle phases are still present at defects like grain boundaries at 1050 °C, with the surface of precipitates showing corrosion pits. Materials exhibit increasing strength and hardness initially with temperature and annealing time, followed by a decrease. Meanwhile, fracture elongation shows a positive correlation with temperature but a negative correlation with time. After annealing at 1050 °C for 500 h, GH3536 retains its high-temperature softening behavior and elongation at fracture, demonstrating excellent plastic stability. Furthermore, the mechanism of high temperature and hydrogen affecting metals is expounded, providing reference for the selection and optimization of materials which service in high temperature and hydrogen.

The effect of crystallographic orientation on globularization and texture evolution during the annealing of a near α titanium alloy tube

In order to weaken the rolling texture of the cold-rolled tube and improve its secondary forming ability, this paper studies the influence mechanism of different annealing times on the microstructure and texture evolution of Ti-6Al-3 Nb-2Zr-1Mo tube after intermediate-temperature annealing. The results show that as the annealing time increases from 30 minutes to 120 minutes, the degree of globularization of α/β phases significantly increases. The globularized structure mainly consists of equiaxed α particles, which are surrounded by necklace-like globularized β phases. The original rolling texture component did not change after 30-minute annealing. The intensity of the rolling texture was weakened, and two new components appear after 120 minutes of annealing. The appearance of these two components was caused by the growing up of globularized α phases close to the Burgers orientation relationship (BOR) with surrounding β phases during a long annealing process. Moreover, it was observed that globularization to some extent broke the BOR between α phase and the adjacent β phase.

Effect of Annealing on the Microstructure, Texture, and Properties of Cold-Rolled Ti50Ni47Fe3 Shape Memory Alloy Sheets

A systematic study was conducted on the impact of annealing treatments on the microstructure and properties of cold-rolled Ti50Ni47Fe3 alloys using optical microscopy, scanning electron microscopy, electron backscattered diffraction, and an electronic universal testing machine. It was found that, during low-temperature annealing (400 °C and 500 °C), the annealing time had no significant effect on the microstructure or properties of the Ti50Ni47Fe3 alloy. Only elongation (δ) increased with the increase in the annealing time, and the grain orientation of the Ti50Ni47Fe3 alloy was <111>//RD (rolling direction). When annealing at medium–high temperature (600 °C), as the annealing time increased, recrystallization and grain growth processes occurred, resulting in a continuous decrease in strength and an increase in δ. Meanwhile, it was found that the grain orientation of the cold-rolled Ti50Ni47Fe3 alloy changed from <111>//RD during the recovery and recrystallization processes to <101>//RD after the grain growth process. The orientation distribution function cross-section φ2 = 45° results indicate that the texture was mainly distributed along the γ orientation line (φ1 = 0~90°, Φ = 54.7°, φ2 = 45°). When annealed at 400 °C and 500 °C, the texture of the Ti50Ni47Fe3 alloys was (111)[uvw]. When the annealing treatment was 600 °C for 120 min, a (110)[uvw] texture occurred. Additionally, ductile fracture occurred in all specimens, and the crack origin was located on one side of the fracture surface, with obvious “Y”-shaped propagation. This article studied annealing treatments of cold-rolled Ti50Ni47Fe3 alloys, providing corresponding theoretical guidance for subsequent production applications.

Microstructural evolution during the crystallization process of sol-gel derived PbZrO3 nanocomposite thin films

For the application of dielectric materials in energy storage, nanocomposition is one of the effective methods to improve their electric breakdown field strength. In this study, PbZrO3-Al2O3 nanocomposite films were prepared by combined thermal evaporation deposition and a sol–gel method. By changing the annealing time, the crystallization process of PbZrO3 matrix and the formation mechanism of Al2O3 nanoparticles were studied, and the microstructure evolution process of composite films was elucidated. The results indicate that before the final annealing at 700 ℃, Al atoms have diffused into the amorphous PbZrO3 film, and some fine grains of the perovskite phase have been generated at the bottom of the film. As the annealing time increases, the perovskite grains grow along the out of plane direction of the thin film to form columnar grains, and Al atoms diffuse into the perovskite phase lattice; As the annealing time further increases, Al2O3 nanoparticles began to precipitate at the interlayer interfaces of PbZrO3 coating layers, forming a layered distribution. The changes in electric properties with annealing time also demonstrate the microstructural evolution process of the composite film during annealing. Therefore, controlling annealing time is an effective means to control the microstructure and electric properties of composite films prepared by the new method for the application of energy storage.

Plasma Anneal As a Stress Control Method in Low Temperature Al2O3 ALD Coatings

The control of mechanical physical stress is an important requirement in a variety of applications, such as flexible electronics or thick optical coatings where film stress can cause delamination. Traditionally, in thermal ALD it has been difficult to control the stress. Al2O3 deposited at low temperature is consistently found to have a tensile stress level in the range of a 300 to 450 MPa ( refs 1-3). It is well established that In magnetron sputtering , film stress can be controlled straightforwardly using the Argon pressure during deposition, as this affects the level of bombardment of the growing film with energetic particles.Paranjpe et al ( ref 1) have demonstrated that the use of a plasma anneal leads to densification and transition of the stress from tensile to compressive. The process consists of a sequence of deposition of a thin layer ( e.g. 5 nm) by thermal ALD, followed by exposure to a low energy plasma. The atomic displacements caused by low energy ions from the plasma tend to lead to filling of nanoscopic voids and point defects, thus releasing tensile stress.In this presentation, we will review an in depth study of the effect of various process parameters on the ability of a capacitively coupled in-situ plasma anneal to control stress. The following parameters will be reviewed: Gas composition: Argon plasmas, Oxygen plasmas and Argon oxygen mixtures are compared. Gas Pressure: The effect of gas pressure on plasma characteristics and the resulting modification of the coating is studied RF Power: RF Power was varied between 0 and 300 W ( 1.32 W/cm2) Plasma duration : The duration of the plasma treatment was varied from 0 to 60 seconds.A process window was identified where the plasma anneal can be used as an effective, controllable tool to reduce stress in the coatings. This is illustrated in fig. 1, which shows the substrate warpage (“bow”) observed in 75 mm thick PET foils with a 50 nm Al2O3 coating deposited at 90 °C. It can be seen that the untreated coating (0 sec plasma) has a bow corresponding to a tensile stress of 370 MPa, in accordance with literature values. As the plasma anneal time increases, the stress value decreases. Applying a 60 sec plasma every 5 nm allows to deposit a virtually stress free coating. Simultaneously with the stress reduction, an increase of the optical index and a slight reduction of the thickness are observed, consistent with a densification of the coating.

Effects of annealing treatment on microstructure and mechanical properties of laser melting-deposited VCoNi medium-entropy alloy

Additive manufacturing (AM) is a promising approach to producing high- or medium-entropy alloys (HEAs or MEAs) with excellent properties. However, some undesirable microstructural defects and unstable precipitated phases were formed owing to the repeated heating and cooling steps and the rapid solidification nature of the AM process. Annealing treatment after AM fabrication is often beneficial for adjusting the comprehensive mechanical properties and stabilizing the microstructures. In this study, a VCoNi MEA single wall sample was fabricated successfully via laser melting deposition (LMD), and the effects of post-annealing treatments on the microstructures and mechanical properties were explored. The grain size and σ-phase particle size increase and the σ-phase particles undergo fragmentation, spheroidization, and coarsening during annealing. As the annealing time increases, the tensile strain increases, but the tensile strength decreases. An excellent combination of strength and ductility can be obtained after annealing for 1.5 h (The yield strength, ultimate tensile strength, and tensile strain are 741.2 MPa, 1287.8 MPa, and 30.5 %, respectively). HDI hardening is the most important strengthening mechanism in this work. The decrease in tensile stress after the annealing treatment is mainly attributed to the decrease of heterogeneity of microstructure, and the increase in tensile strain after the annealing treatment is mainly attributed to the decrease of the pores and the spheroidization of the rod-like σ-phase particles. This work provides practical insight into adjusting the microstructure and comprehensive mechanical properties of HEAs and MEAs for AM.

Effect of recrystallization annealing on microstructure and properties of cold-deformed CoCrCu1.2FeNi high entropy alloy

In this paper, CoCrCu1.2FeNi high entropy alloy (HEA) was prepared by vacuum suspension melting. After 50 % cold-deformation, recrystallization annealing experiments involving the annealing temperatures of 650–950 ℃ and the annealing times of 30–120 min were carried out on the cold-deformed HEA. The microstructure and properties of the alloy were compared before and after annealing. The results showed that with the extension of annealing time and temperature, the microstructure of the alloy was gradually uniform and coarsening occurred after spheroidization. In addition, fusion and engulfment occurred in the microstructure and the microstructure size decreased first and then increased. Both the fracture strength and fracture strain of the alloy increased first and then decreased. The alloy had the best compression performance at 850 ℃/60 min. Compared with the alloy after cold-deformation, the fracture strength was increased by 79.3 %, the fracture strain was increased by more than 1 time, and the comprehensive mechanical properties were the best at 750–850 ℃. The average hardness decreased with the increase of temperature and annealing time, and the initial recrystallization temperature of the alloy was determined to be about 650 ℃. The formation of annealing twins refined the microstructure and improved the properties of the alloy.

Study of 3D binder-free silicide/silicon anodes for lithium-ion batteries

Silicon anode materials have attracted much attention as an alternative to the graphite anode in Li-ion batteries since the theoretical capacity of silicon is an order of magnitude higher than that of graphite. However, the drastic volume changes of silicon during lithiation/delithiation cause breakup of the electrode, electrical isolation of the active material and capacity fade. Binders and conducting agents, while improving adhesion and electrical conductivity, reduce the volumetric capacity of the Si anodes. In this article, we present the study of improved, easy-to-fabricate binder-free 3D silicon anodes. The anodes are prepared by combining for the first time three approaches: use of Si nanoparticles, use of porous, high-surface-area metal foam current collector and formation of metal silicide layer in between. The fabrication of 3D anodes includes electrophoretic deposition of silicon nanoparticles (SiNP) on copper, nickel, and titanium foams followed by annealing at different temperatures and time. Analysis of morphology and electrochemical performance of composite 3D silicon/silicide anodes reveals that increased annealing time of SiNPs-deposited on Ni foam results in a thicker Ni3Si2 layer, which leads to the enhanced capacity retention and power capability. At C/10 and C/2 rates the reversible capacity of NMC/3DSi-Ni3Si2 cells was 880 and 530 mAh/gSi+Silicide, respectively.

Study on the recrystallization microstructure and texture evolution of a rolled 0.075 mm ultra-thin grain-oriented silicon steel

This paper investigated the recrystallization behavior of a rolled 0.075 mm ultra-thin grain-oriented silicon steel, and microstructure and texture evolutions were studied. At the early stage, dominant {hk0}<001> recrystallized grains were ascribed to the preferential {hk0}<001> nucleation, then their growth was reduced by texture pinning effect. In contrast, a few ‘random’ grains grew excessively to consume surrounding {hk0}<001> fine-grained matrix, meanwhile nuclei originating from initial non-Goss grains also showed size advantage and further grew. Despite of quasi-two-dimensional microstructure of ultra-thin sheet, the anisotropic surface energy did not show marked effect on grain growth difference. Those coarse grains, which were 10 times larger than the matrix grains, were surrounded by high energy (HE) boundaries, indicating that their growth was driven by high grain boundary mobility. With the increasing annealing time, the formation of {hk0}<001> oriented assemblies and the growth of non-{hk0}<001> oriented grains contributed to the overall grain size increase. Regarding the relationship between microstructure, texture and magnetic properties, {hk0}<001> texture was weakened and reduced magnetic induction accordingly, and the combination of growing while heterogeneous grain size and changing texture made iron loss a first decrease and then increase tendency. It is essential to control annealing time to obtain suitable combination of microstructure and texture.

Investigation of Recrystallization Kinetics in 1050 Al Alloy by Experimental Evidence and Modeling Approach.

The recrystallization (RX) kinetics of commercially pure Al alloy is studied under the scope of annealing temperature, time, and degree of deformation. To examine the distribution of recrystallization, Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory is employed, where the path of microstructural transformation from the deformed state to the fully recovered one is studied as a function of the volume fraction of recrystallized grains (XV) and annealing time. The drop in hardness is recorded for the samples at various stages of annealing with a corresponding decrease in stored energy as the annealing time increases. The stored energy obtained from the hardness results and Orientation Imaging Microscopy (OIM)-based method is found to be in good agreement with each other, proving the efficiency of both techniques. To determine the volume fraction of the recrystallized microstructure, data obtained from Vickers hardness measurements are used. Various parameters associated with recrystallization statistics such as the critical radius of nuclei, the incubation period, and the mobility of High-Angle Grain Boundaries (HAGB) were derived from the experimental evidence. The experimental data also suggest a sharp drop in the velocity of HAGB as the RX transformation process approaches its completion, which is found to be a direct result of a drop in stored energy. A softening window between 42 s and 55 s is identified for our experimental data where the hardness, stored energy, and velocity of HAGB drops very sharply, and the maximum fraction of deformed grains is expected to be converted to the recrystallized ones. Along with experimental observations, an analytical model was developed, which helps to approximate the kinetics of RX and corresponding parameters for various annealing temperatures and strains while revealing the characteristic feature of Avrami exponent n. Both experimental evidence and model data reveal a very strong dependency of recrystallization behavior on the stored energy.

Superior comprehensive properties of LaFe11.8Si1.2/Ce60Co40 magnetocaloric composites

LaFe11.8Si1.2/10 wt%Ce60Co40 composites were prepared by spark plasma sintering and subsequent diffusion annealing. A novel core–shell structure is observed with the LaFe11.8Si1.2 particles as the core and the (La,Ce)2(Fe,Co,Si)17 (2:17) phase as the shell. As diffusion annealing time (ta) increases, this core–shell structure is replaced by the formation of the (La,Ce)1(Fe,Co,Si)13 phase. Annealing at 1323 K for 12 h results in samples with (−ΔSM)max of 9.30 J/(kg·K) (Δμ0H = 2 T), good mechanical properties ((σbc)max = 402 MPa, ε = 4.21%) and thermal conductivity of 8.7 W/(m·K). Thus, bulk composites with excellent comprehensive properties for magnetic refrigeration are obtained in this work.

Microstructure Evolution with Rapid Thermal Annealing Time in (001)-Oriented Piezoelectric PZT Films Integrated on (111) Si.

In our recently published paper (Y.-Y. Wang et al., High performance LaNiO3-buffered, (001)-oriented PZT piezoelectric films integrated on (111) Si, Appl. Phys. Lett. 121, 182902, 2022), highly (001)-oriented PZT films with a large transverse piezoelectric coefficient e31,f prepared on (111) Si substrates were reported. This work is beneficial for the development of piezoelectric micro-electro-mechanical systems (Piezo-MEMS) because of (111) Si's isotropic mechanical properties and desirable etching characteristics. However, the underlying mechanism for the achievement of a high piezoelectric performance in these PZT films going through a rapid thermal annealing process has not been thoroughly analyzed. In this work, we present complete sets of data in microstructure (XRD, SEM and TEM) and electrical properties (ferroelectric, dielectric and piezoelectric) for these films with typical annealing times of 2, 5, 10 and 15 min. Through data analyses, we revealed competing effects in tuning the electrical properties of these PZT films, i.e., the removal of residual PbO and proliferation of nanopores with an increasing annealing time. The latter turned out to be the dominating factor for a deteriorated piezoelectric performance. Therefore, the PZT film with the shortest annealing time of 2 min showed the largest e31,f piezoelectric coefficient. Furthermore, the performance degradation occurred in the PZT film annealed for 10 min can be explained by a film morphology change, which involved not only the change in grain shape, but also the generation of a large amount of nanopores near its bottom interface.

Effect of annealing by CO2 laser on Structural and optical properties of zinc oxide thin films prepared by Sol – gel method

Laser heat treatment is one of the important industrial applications of laser and being studied at the present time as a substitute for conventional thermal annealing. In this research (ZnO) thin films have been deposition on a glass by (Sol - Gel / Spin Coating) technique and annealed by two ways, the first one using a convection oven, where they were annealing with three temperatures (400, 500, 600) °C for one hour, and the second way using a continuous (CO2) laser with (10.6 μm) wavelength and (10 W) power and three intervals (10, 15, 20) min, were studied structural and optical properties of membranes prepared by both ways to determine the effect of laser annealing on them, and the results of (XRD) tests showed that these membranes with the structural of multi-crystalline hexagon compact type and increase the degree of temperature oven annealing, as well as increasing the duration of the laser annealing lead to increased volumes of granular membranes rates. The results of the (AFM) tests to the topography of the surfaces of the membranes to be of crystalline uniformity and homogeneity superficially good, especially for laser annealed membranes. The results of optical examinations of these membranes also showed that they having high permeability, especially in the regions of the visible spectrum and the near-infrared and increased with increase the degree of oven annealing temperature and the duration of laser annealing, and less energy gap of these membranes values with increase the temperature degree of annealing or increase of laser annealing time, In addition the optical properties studied in this research included absorbance, reflectivity, refractive index, coefficients of absorption and extinction, and real and imaginary dielectric constants.