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Fe₂O₃ thin films were deposited on alumina substrates by using the physical vapor deposition technique “RF magnetron sputtering”. The impact of the thermal treatment on the structural, optical and morphological properties was systematically investigated. The results of the structural characterizations reveal that the elaborated thin films present a main peak whichcorresponds to the crystalline plane (104) of the hematite ($\alpha$-Fe₂O₃). Furthermore, the Raman spectra confirm the existence of the hematite phase of the iron oxide. UV-Visible spectrophotometer analysis of Fe₂O₃ thin films before and after annealing shows that the transmittance increases with heat treatment. Moreover, the heat treatment at 500^∘C significantly improves the absorption coefficient $\alpha$, extinction coefficient k, refractive index n, and the band gap of Fe₂O₃ thin films. Furthermore, a spinel polarization change was found to be responsible for the ferrobehavior of Fe₂O₃ thanks to the lattice crystallinity enhancement. The density functional theory calculations demonstrate that the magnetic properties are very sensible to any induced strain in the Fe₂O₃ lattices.

The lack of ductility is known to be one of the major drawbacks of amorphous state. Recently, an increase in the tensile strength and ductility was found in the ${\text{Ni}}_{82.1}$${\text{Cr}}_{7.8}$${\text{Si}}_{4.6}$${\text{Fe}}_{3.1}$${\text{Mn}}_{0.2}$${\text{Al}}_{0.1}$${\text{Cu}}_{0.1}$B₂ metal glass ribbon pre-annealed at $\beta$-relaxation temperature. This paper analyzes the surface relief transformation observed during this process and the nature of separate inhomogeneities. The most significant effect is a flattening of the surface relief. This case was confirmed by statistical processing. Thus, the surface relief change was shown to be a clear indicator of structure relaxation process, that occurs in a metal glass ribbon well below its crystallization.

We have fabricated, characterized and compared the performance of lateral enhancement-mode GaN MOSFETs on as-grown and RIE-etched surfaces with 900 and 1000°C gate oxide annealing temperatures. Both subthreshold swing and field effect mobility show 1000°C is the optimal annealing temperature for the PECVD gate oxide in our MOSFET process.

The thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA) of the as-deposited and electrochemically oxidized Hg₁Ba₂Ca₁Cu₂O_6+δ(Hg-1212) samples were carried out in air, flowing oxygen and nitrogen environment in order to estimate the thermal decomposition temperature and hence to maintain the annealing temperature and atmosphere. After annealing, electrochemically synthesized films showed an increase in T_c from 104.7 K to 119 K and J_c values from 1.43×10³ to 4.3×10³A/cm². Electrochemically oxidized Hg-1212 films in under-, optimally- and over-doped states were irradiated with a Red He–Ne laser (2mW) and the T_c was found to increase from 104.7 K to 106 K and J_c from 1.43×10³ to 1.89×10³A/cm². The effects of annealing and photo-irradiation on structural, microstructural and superconducting properties of electrochemically synthesized Hg-1212 films were investigated and discussed in detail in this paper.

Aluminum antimonide (AlSb) is thought to be a potential material for high efficiency solar cells. In this paper, AlSb thin films have been fabricated by DC magnetron sputtering on glass substrates. The sputtering target consists of aluminum and antimony, and the area ratio of Al to Sb is 7:3, which is derived from research into the relationship between the deposition rates of both the metals and sputtering power. XRD and AFM measurements show that the as-deposited films are amorphous, but become polycrystalline with an average grain size of about 20 nm after annealing in an argon atmosphere. From optical absorption measurements of annealed AlSb films, a band gap of 1.56 eV has been demonstrated. Hall measurements show that the films are p-type semiconductors. The temperature dependence of dark conductivity tested in vacuum displays a linear lnσ to 1/T curve, which indicates a conductivity activation energy of around 0.61 eV.

In this study, the (FePt)_100-xCu_x (x=0, 4.6, 6.7, 8.8, 10.9) (FePtCu) alloy films were prepared by co-sputtering. The effects of Cu addition content and heat treatment on the nanostructure and magnetic properties of the polycrystalline (FePt)_100-xCu_x films are reported. The experimental results show that the ordering temperature of the (FePt)_100-xCu_x (x=6.7) films reduced to 320°C, which is much lower than that of the FePt alloy. After heat treatment at 600°C for 1 hour, the (FePt)_100-xCu_x (x=6.7) film shows a coercive force of 15 kOe and the magnetization of 576 emu/cc. The magnetic properties of the FePtCu films can be adjusted by varying the Cu content in the films. The enhancement of the magnetic properties of the FePtCu films mainly resulted from the formation of the order L1₀ phase. DSC traces of as-deposited disorder films at different heating rates, to evaluate the crystallization of the order phase, showed that the addition of Cu atoms reduced the activation energy of ordering from 217 kJ/mol to 87 kJ/mol for the (FePt)_100-xCu_x films (x= 0 and 6.7, respectively). The reduction of the ordering temperature and corresponding activation energy might due to the solid solution of the Cu atoms in the FePt films.

Giant magnetostrictive (Tb_0.28Dy_0.72)Fe_1.90 thin films were deposited on Si (111) substrates at room temperature by pulsed laser deposition (PLD). The crystalline state and the magnetic properties of the samples were investigated in relation to the different annealing temperatures T_a, which varied between 623K and 923K. X-ray diffraction results indicated the films are in amorphous state after annealing at T_a = 623K-823K for 1h, and were partially crystallized at T_a = 923K for 1h. Meanwhile, the annealing treatment showed a great influence on the magnetic anisotropy. The orientation of the magnetic easy axis of the as-deposited films changed from perpendicular to parallel to the film plane after annealing treatment. The mechanism of the transformation of the magnetic easy axis was explained in terms of the tensile stress which is formed due to the difference in the thermal expansion coefficients of the thin film and substrate.

Recrystallization behavior of a nickel-base single crystal superalloy cold-deformed by compression has been investigated. The effects of plastic strain, annealing temperature and annealing time have been studied, and recrystallization diagram has been obtained. It has been found that a very strong dependence upon temperature is evident. For the single crystal superalloy with 4.5% strain, full recrystallization has been observed when annealing at 1300°C for 1h, surface recrystallization at 1250°C for 1h, cellular recrystallization at 1150°C for 1h and no recrystallization at 1100° for 1h. With the drop of temperature, the volume fraction of γ′ phase increases, which incrementally restricts recrystallized boundary migration. With the increasing of annealing time or strain, the sensitivity of recrystallization increases. Recrystallization tendency of standard- heat-treated superalloy is weaker than that of as-cast single crystal superalloy, because standard heat treatment reduces the microsegregation, lowers the eutectic amount and forms homogeneous γ1 phase distribution, which decrease preferential nucleation site of recrystallized grain and increase the resistance of boundary migration of recrystallization.

Self-formation of MgO or Al₂O₃ surface layer on CuMg or CuAl alloys by annealing in H₂ gas was investigated theoretically and experimentally. Theoretical consideration shows that Mg or Al can segregate to the surface of Cu during the annealing, while the enrichment ability is much stronger for Mg. Meanwhile, the MgO or Al₂O₃ surface layer is self-formed by the preferential reaction of Mg or Al with O₂ remnant in H₂ atmosphere. The Al₂O₃ surface layer is expected to play a role in passivating the surface of Cu. However, the MgO layer would suffer failure in passivating the surface due to incorporation of Cu and fissures formed in MgO during the annealing process. Our theoretical predictions are in agreement with experimental observations.

Silicon oxycarbide (SiCO) thin films were prepared by the RF reactive sputtering technique on n-type silicon substrates with the target of sintered silicon carbide (SiC), and high purity oxygen was used as the reactant gas. The as-deposited films were annealed at temperatures of 600^°C, 800^°C, and 1000^°C under nitrogen ambient, respectively. The films were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and photoluminescence (PL) spectrophotometer. The results show that annealing temperature plays an important role in the structure and photoluminescence of the films. The temperature 600^°C is the most favorable annealing temperature for SiO₂ crystallization and the formation of 6H-SiC crystal phase in the SiCO films. The intense PL peaks located at 375 nm and 470 nm are observed at room temperature. The origin of the PL was discussed.

Ge-doped (Cu_0.5Tl_0.5)Ba₂Ca₃(Cu_4-yGe_y)O_12-δ (y = 0, 0.3, 0.6 and 0.9) superconductors have been synthesized at normal pressure through solid state reaction method. Ge has been doped in the CuO₂ planes constituting the superconducting block of these structures. In the as-prepared samples, a suppression of the critical temperature is observed with increased Ge concentration. The suppression of the critical temperature can be attributed to the decreased number of carriers due to their localization at Ge⁴⁺ ions. Ge-doped post-annealed samples have shown enhancement in the critical temperature as well as magnitude of diamagnetism. Oxygen annealing seems to have replenished the charge carries through the process of hole doping in CuO₂/GeO₂ planes, thereby bringing the carrier density closer to the optimum level. Oxygen related phonon modes have also been investigated. A shift in peak positions of the apical and planar oxygen related modes have been observed while modes associated with O_δ oxygen atoms seem stable in both cases of Ge doping and oxygen annealing.

We present a study of the influence of annealing and doping on the electrical properties of few-layer (FL) MoS₂ films on Si and quartz substrates deposited using a self-designed metal sulfide chemical vapor deposition (MSCVD) system. FL MoS₂ slices obtained through MSCVD, in the size range of 50–200 nm, were found to be uniformly scattered on the substrates. The conductivity and mobility of these films are greatly enhanced after annealing at 650–850°C. The largest mobility measured for pure MoS₂ on quartz substrate is 6.4×10³cm²/Vs, almost two orders of magnitude larger than that of bulk MoS₂ (500 cm²/Vs). We deduce that the superior charge carrier mobility in our sample is mainly attributed to reduced phonon scattering because of a lower carrier density (10¹⁰-10¹¹ cm^-2) compared to previously documented values (10¹²-10¹³cm^-2). Additionally, the conductivity and carrier concentration of FL MoS₂ films were enhanced by about two orders of magnitude compared to those of the as-grown films doped with Cu, Na and Ag ions but not doped with B ions. The films doped with Na and Ag exhibit characteristic p-type conductivity, while those doped with Cu and B exhibit n-type conductivity. Moreover, the MoS₂/Si heterojunction exhibited good rectification characteristics and excellent conductivity, indicating that the FL MoS₂ films will find many applications in high-efficiency nanodevices.

Annealing study of amorphous bulk and nanoparticle iron at temperatures from 500 K to 1000 K has been carried out using molecular dynamics (MD) simulations. The simulation is performed for models containing 10⁴ particles Fe at both crystalline and amorphous states. We determine changes of the potential energy, pair radial distribution function (PRDF) and distribution of coordination number (DCN) as a function of annealing time. The calculation shows that the aging slightly reduces the potential energy of system. This result evidences that the amorphous sample undergoes different quasi-equilibrated states during annealing. Similar trend is observed for nanoparticles sample. When the samples are annealed at high temperatures we observe the crystallization in both bulk and nanoparticle. In particular, the system undergoes three stages. At first stage the relaxation proceeds slowly so that the energy of system slightly decreases and the samples structure remains amorphous. Within second stage a structural transformation occurs which significantly changes PRDF and DCN for the relatively short time. The energy of the system is dropped considerably and the amorphous structure transforms into the crystalline. Finally, the crystalline sample undergoes the slow relaxation which reduces the energy of system and eliminates structural defects in crystal lattices.

Indium oxide (In₂O₃) pyramidal nano and microstructures were prepared by a thermal evaporation and condensation method. The preannealing step affected the nanostructures morphologies and their sensing capability. The nanosize structures have been fabricated in nucleated preorganized situation. By changing from prepared sites to undesired sites, the morphology was deteriorated. The synthesized In₂O₃ structures were characterized by field emission scanning electron microscopy (FESEM) and the X-ray diffraction (XRD) measurements. The FESEM images showed that nanostructures with 100–250 nm in size were fabricated. The XRD patterns indicated that most of the samples are crystalline. Then, the fabricated structures were investigated for H₂S gas sensing. The nanocrystal pyramids were found to be sensitive to as low as 100 ppb of H₂S gas at room temperature and microcrystal ones to 300 ppb. The nanopyramids demonstrated that they were very sensitive to gas presence and their response and recovery time were in a few seconds.

This study began by preparing gallium oxide (Ga₂O₃) doped with zinc fluoride (ZnF₂) and manufacturing a target material. Subsequently, electron beam (e-beam) deposition was employed to coat silicon substrates with the prepared material. Different heat treatment conditions were applied to the deposited films, followed by material and electrical property analyses. The investigation explored the impact of pre-sintering Ga₂O₃ at 950°C to transform it into a more stable $\beta$-phase. For comparative purposes, some samples underwent annealing at 600°C in a nitrogen–hydrogen (95% N${}_2+5\%$ H₂, abbreviated as N${}_2+{\mathrm{\text{H}}}_2$) mixed gas, which was used as a reduction atmosphere, to increase oxygen vacancies in the ZnF₂-doped Ga₂O₃ thin films and consequently enhance their conductivity. The deposited ZnF₂-doped Ga₂O₃ thin films initially exhibited an amorphous phase, with diffraction peaks appearing only after a 600°C annealing process. Pre-sintering Ga₂O₃ powder at 950°C promoted the emergence of the $\beta$-phase, and the bandgap value increased after annealing. Measurements using B1500A revealed that sintering and annealing ZnF₂-doped Ga₂O₃ thin films were essential steps to enhance their conductivity. X-ray photoelectron spectroscopy (XPS) further confirmed a significant correlation between the conductivity variation and the concentration of oxygen vacancies. Additionally, it was observed that the use of an N${}_2+{\mathrm{\text{H}}}_2$ mixed gas further increased the presence of oxygen vacancies in the films. The results of this study provide an important method to make Ga₂O₃ thin films with conductivity, which can be utilized in the fabrication of Ga₂O₃ thin-film-based semiconductor devices in the future.

La_0.5Ca_0.5MnO₃ (LCMO) thin films grown by pulsed laser deposition (PLD) and annealed at different temperatures were investigated by high angle X-ray diffraction, atomic force microscope (AFM), scanning electron microscope (SEM), and energy dispersive spectroscopy (SEM-EDS). The lattice parameters, surface morphology as well as the metal compositions of the films were obtained. It was found that the surface morphology of the films strongly depends on the annealing temperatures. The difference of the thermal expansion coefficients between the film and the substrate plays an important role in determining the morphology of the film surface. It induces an in-plane compressive stress in the LCMO films. The strains in the film can be relaxed by nanoscale grains and cracks.

The effects of annealing temperature on the optical properties of nitrogenated amorphous carbon (a-C:N) films grown on quartz substrates by a novel surface wave microwave plasma chemical vapor deposition (SWMP-CVD) method are reported. The thickness, optical, structural and bonding properties of the as-grown and anneal-treated a-C:N films were measured and compared. The film thickness decreased rapidly with increasing annealing temperature above 350°C. A wide range of optical absorption characteristics is observed, depending on the annealing temperature. The optical band gap of as-grown a-C:N films is approximately 2.8 eV, gradually decreasing to 2.5 eV for the films anneal-treated at 300°C, and beyond that decreasing rapidly down to 0.9 eV at 500°C. The Raman and FTIR spectroscopy measurements have shown that the structural and composition of the films can be tuned by optimizing the annealing temperature. The change of optical, structural and bonding properties of SWMP-CVD-grown a-C:N films with higher annealing temperature was attributed to the fundamental changes in the bonding and band structures of the films.

The inhomogeneity of Schottky barrier height (SBH) in nickel silicide/Si contacts was observed by the internal photoemission spectroscopy. New Fowler equations were introduced to analyze the observed properties. We assumed that two or three regions with different SBHs coexist in Ni silicide/Si contacts, and then the individual barrier height was evaluated. We found that SBH increases monotonously with the increase of annealing temperature in the case of T_annealing<600°C. When T_annealing is 600°C, SBH becomes maximal, then decreases monotonously with the increase of annealing temperature in the case of T_annealing > 600°C. The formation of the two regions (Regions II and III) in nickel silicide/Si Schottky contacts annealed at different temperatures, was explained by the model of the Fermi-level pinning or the metal-induced gap states.

Stimulated emission has been observed from oxide structure of silicon when optically excited by 514 nm laser. The twin peaks in the region from 690 nm to 700 nm are dominated by stimulated emission which can be demonstrated by its threshold behavior and transition in linear evolution. The oxide structure was fabricated by laser irradiation and annealing treatment on silicon. A model for explaining the stimulated emission has been proposed in which the trap states of the interface between oxide of silicon and porous nanocrystal play an important role.

Ni-rich intermetallic compound Ni₃Al films were deposited using the dual-target magnetron co-sputtering method. The grain-boundary and grain-size characteristics of the as-deposited and post-annealed Ni₃Al films were investigated using a slow positron beam. The results demonstrate a distinct change of S-parameter and positron effective diffusion length L_eff values as samples were annealed at different ambient atmospheres and temperatures. It shows that the positron trapping center is mainly associated with intergranular vacancies, and changes to either the vacancy cluster size or the grain size have been invoked to explain the changes of the values of the S-parameter and L_eff. Ni-rich oxygen-Ni₃Al films were also studied. All films were identified using X-ray diffraction and the results confirm the conclusion obtained by the slow positron beam.