Impact of annealing temperature on the ferroelectric properties of W/Hf_(0.5)Zr_(0.5)O_(2)/W capacitor

Crystallization annealing is a crucial process for the formation of the ferroelectric phase in HfO_(2)-based ferroelectric thin films.Here,we systematically investigate the impact of the annealing process,with temperature varied from 350℃to 550℃,on the electricity,ferroelectricity and reliability of a Hf_(0.5)Zr_(0.5)O_(2)(HZO;7.5 nm)film capacitor.It was found that HZO film annealed at a low temperature of 400℃can effectively suppress the formation of the monoclinic phase and reduce the leakage current.HZO film annealed at 400℃also exhibits better ferroelectric properties than those annealed at 350℃and 550℃.Specifically,the 400℃-annealed HZO film shows an outstanding 2Pr value of 54.6μC·cm^(-2)at±3.0 MV·cm^(-1),which is relatively high compared with previously reported values for HZO film under the same electric field and annealing temperature.When the applied electric field increases to±5.0 MV·cm^(-1),the 2Pr value can reach a maximum of 69.6μC·cm^(-2).In addition,the HZO films annealed at 400℃and 550℃can endure up to bout 2.3×10^(8)cycles under a cycling field of 2.0 MV·cm^(-1)before the occurrence of breakdown.In the 400℃-annealed HZO film,72.1%of the initial polarization is maintained while only 44.9%is maintained in the 550℃-annealed HZO film.Our work demonstrates that HZO film with a low crystallization temperature(400℃)has quite a high ferroelectric polarization,which is of significant importance in applications in ferroelectric memory and negative capacitance transistors.

Effects of annealing temperature on the microstructure and properties of the 25Mn-3Si-3Al TWIP steel

Microstructures and mechanical properties of the 25Mn twinning induced plasticity （TWIP） steel at different annealing temperatures were investigated. The results indicated that when the annealing temperature was 1000℃, the 25Mn steel showed excellent comprehensive mechanical properties, the tensile strength was about 640 MPa, the yield strength was higher than 255 MPa, and the elongation was above 82%. The microstructure was analyzed by optical microscopy （OM）, X-ray diffraction （XRD）, and transmission electron microscopy （TEM）. Before deformation the microstructure was composed of austenitic matrix and annealing twins at room temperature; at the same time, a significant amount of annealing twins and stacking faults were observed by TEM. Mechanical twins played a dominant role in deformation and as a result the mechanical properties were found to be excellent.

Effect of annealing temperature on microstructure and electrochemical performance of La_(0.75)Mg_(0.25)Ni_(3.5)Co_(0.2) hydrogen storage electrode alloy

To improve the cyclic stability of La-Mg-Ni system alloy, as-cast La0.75Mg0.25Ni3.5Co0.2 alloy was annealed at 1123, 1223, and 1323 K for 10 h in 0.3 MPa argon. The microstructure and electrochemical performance of different annealed alloys were investigated systematically by X-Ray Diffraction （XRD）, Scanning Electron Microscopy （SEM）, X-Ray Photoelectron Spectroscopy （XPS）, and electrochemical experiments. The results obtained by XRD and SEM showed that the as-cast and annealed （1123 K） alloys had multiphase structure containing LaNis, （La, Mg）2（Ni, Co）7 and few LaNi2 phases. When annealing temperatures approached 1223 and 1323 K, LaNi2 phase disappeared. The annealed alloys at 1223 and 1323 K were composed of LaNi5, （La, Mg）2（Ni, Co）7 and （La, Mg）（Ni, Co）3 phases. With increasing annealing temperature, the maximum discharge capacity of the alloy decreased monotonously, but the cyclic stability was improved owing to structure homogeneity and grain growth after annealing, as well as the enhancement of anti-oxidation/corrosion ability and the suppression of pulverization during cycling in KOH electrolyte.

Annealing Temperature Effects of TiO2 Nanofiber Anodes for the Rechargeable Lithium Ion Batteries

TiO2 nanofibers（TiO2/NFs） have been synthesized through an electrospinning method and annealed at 400, 500 and 600 ℃ to optimize their systems. The effects of annealing temperature on the electrochemical properties for lithium ion batteries（LIBs） are assessed. The obtained LIB properties for TiO2 nanofiber anodes annealed at 400 ℃（denoted as TiO2/NFs-400） are much better than those of TiO2/NFs-500 and TiO2/NFs-600. The TiO2/NFs-400 anodes show good LIB performance with capacities of 180 and 150 m Ah/g tested at 200 and 600 m A/g after 100 cycles with almost no capacity loss and superb rate performance. The XRD results show that the pure anatase phase TiO2 can form at 400 ℃ for TiO2/NFs-400, while mixed phases of anatase and rutile are emerged at TiO2/NFs-500 and TiO2/NFs-600. Furthermore, the TiO2 nanoparticles are combined in nanofibers, and their corresponding crystal particle size for TiO2/NFs-400 was smaller than that of the other two samples. It is concluded that the superior electrochemical performance of the TiO2/NFs-400 anodes could be due to their pure crystal of anatase, small nanoparticles and non-ideal crystal lattices.

Effect of Annealing Temperature on the Formation of Silicides and the Surface Morphologies of PtSi Films

The effect of annealing temperature on the formation of the PtSi phase. distribution of silicides and the surface morphologies of silicides films is investigated by XPS. AFM. It is shown that the phase sequences of the films change from Pt-Pt2Si-PtSi-Si to Pt+Pt2Si+PtSi-PtSi-Si or Pt+Pt2Si+PtSi-PtSi-st with an increase of annealing temperature and the reason for the formation of mixed layers is discussed.

Annealing Temperature dependence of Photoluminescence from Silicon-rich silica Films

The silicon-rich silica films were prepared by a dual-ion-beam co-sputtering method from a composite Target in an argon atmosphere. The structure of the films studied by the aid of TEM and XRD is amorphous. The photoluminescence (PL) spectra were found to have a 4- luminescent band peak at 320 nm, 410 nm, 560 nm, and 630 nm, respectively, at room temperature. The intensity and the wavelength position of PL are dependent on annealing temperature (Ta), and the luminescent mechanism is analyzed.

Effect of the annealing temperature on the long-term thermal stability of Pt/Si/Ta/Ti/4H–SiC contacts

The Pt/Si/Ta/Ti multilayer metal contacts on 4H-Si C are annealed in Ar atmosphere at 600°C-1100°C by a rapid thermal processor（RTP）. The long-term thermal stability is evaluated by aging the annealed contact at 600°C in air. The contact＇s properties are determined by current-voltage measurement, and the specific contact resistance is calculated based on the transmission line model（TLM）. Transmission electron microscope（TEM） and energy-dispersive x-ray spectrometry（EDX） are used to characterize the interface morphology, thickness, and composition. The results reveal that a higher annealing temperature is favorable for the formation of an Ohmic contact with a lower specific contact resistance, and causes the rapid degradation of the Ohmic contact in the aging process.

Effects of Annealing Temperature on Microstructure and Sensing Properties to Alcohol for Nano-La_(0.68)Pb_(0.32)FeO_3

La_(0.68)Pb_(0.32)FeO_3 samples annealed at different temperature were prepared using citrate sol-gel method. With increasing of annealing temperature from 200 to 1000 ℃, the samples crystallize to have single-phase perovskite structure. However, the sensitivity increases at first due to the improvement of crystallization of the perovskite phase, and finally drops attributed to the larger grain size. The optimal sensitivities for La_(0.68)Pb_(0.32)FeO_3 samples annealed at 400, 600, 800, and 1000 ℃ are 12.14, 14.77, 51.07, and 34.55, respectively.

Effect of annealing temperature on interfacial and electrical performance of Au-Pt-Ti/HfAlO/InAlAs metal-oxide-semiconductor capacitor

HfAlO/InAlAs metal-oxide-semiconductor capacitor (MOS capacitor) is considered as the most popular candidate of the isolated gate of InAs/AlSb high electron mobility transistor (HEMT). In order to improve the performance of the HfAlO/InAlAs MOS-capacitor, samples are annealed at different temperatures for investigating the HfAlO/InAlAs interfacial characyeristics and the device's electrical characteristics. We find that as annealing temperature increases from 280 ℃ to 480 ℃, the surface roughness on the oxide layer is improved. A maximum equivalent dielectric constant of 8.47, a minimum equivalent oxide thickness of 5.53 nm, and a small threshold voltage of -1.05 V are detected when being annealed at 380 ℃;furthermore, a low interfacial state density is yielded at 380 ℃, and this can effectively reduce the device leakage current density to a significantly low value of 1×10-7 A/cm2 at 3-V bias voltage. Therefore, we hold that 380 ℃ is the best compromised annealing temperature to ensure that the device performance is improved effectively. This study provides a reliable conceptual basis for preparing and applying HfAlO/InAlAs MOS-capacitor as the isolated gate on InAs/AlSb HEMT devices.

Water-based processed and alkoxide-based processed indium oxide thin-film transistors at different annealing temperatures

In this study,indium oxide（In2O3） thin-film transistors（TFTs） are fabricated by two kinds of low temperature solution-processed technologies（Ta ≤ 300℃）,i.e.,water-based（DIW-based） process and alkoxide-based（2-ME-based）process.The thickness values,crystallization properties,chemical structures,surface roughness values,and optical properties of In2O3 thin-films and the electrical characteristics of In2O3 TFTs are studied at different annealing temperatures.Thermal annealing at higher temperature leads to an increase in the saturation mobility（μsat） and a negative shift in the threshold voltage（VTH）.The DIW-based processed In2O3-TFT annealed at 300℃ exhibits excellent device performance,and one annealed at 200℃ exhibits an acceptable μsat of 0.86 cm^2/V·s comparable to that of a-Si：H TFTs,whereas the 2-ME-based TFT annealed at 300℃ exhibits an abundant μsat of 1.65 cm^2/Vs and one annealed at 200℃ is inactive.The results are attributed to the fact that the DIW-based process induces a higher degree of oxidation and less defect states than the 2-ME-based process at the same temperature.The DIW-based process for fabricating the In2O3 TFT opens the way for the development of nontoxic,low-cost,and low-temperature oxide electronics.

The influence of annealing temperature on the morphology of graphene islands

We report on temperature-programmed growth of graphene islands on Ru （0001） at annealing temperatures of 700 ℃, 800 ℃, and 900 ℃. The sizes of the islands each show a nonlinear increase with the annealing temperature. In 700 ℃ and 800 ℃annealings, the islands have nearly the same sizes and their ascending edges are embedded in the upper steps of the ruthenium substrate, which is in accordance with the etching growth mode. In 900 ℃ annealing, the islands are much larger and of lower quality, which represents the early stage of Smoluchowski ripening. A longer time annealing at 900 ℃ brings the islands to final equilibrium with an ordered moire pattern. Our work provides new details about graphene early growth stages that could facilitate the better control of such a growth to obtain graphene with ideal size and high quality.

Effects of Annealing Temperature on the Electrical Conductivity and Mechanical Property of Cu-Te Alloys

The effects of annealing temperatre on the electrical conducitivity and mechanical property of Cu-Te alloys were studied via an AG-10TA electronic universal machine, an SB2230 digital electric bridge, SEM, EDS and XPS. The results show the electrical conductivity increases while the tensile strength fluctuates when the annealing temperature becomes higher because the recrystallization occurs during the annealing process, leading to the density of dislocation decreasing, grain size growing up, but the second phase precipitating sufficiently and simultaneously.

Effect of Annealing Temperature on Magnetic Aftereffect and Positron Lifetime in Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 Alloy

The magnetic aftereffect (MAE) and the positron lifetime were measured at room temperature on the Fe_73.5Cu_1 Nb_3Si_13.5 B_9 alloy in as-cast and after annealing at temperature T_a in the range from 450 to 750℃ It was found that both the MAE and the positron lifetime decrease with increasing T_a when T_≤600℃. While Ta≥650℃, MAE is essentially suppressed, and two positron lifetimes appear.

Effect of continuous annealing temperature on the microstructure and mechanical property of an aluminum killed steel

The continuous annealing process of a typical aluminum killed steel was investigated. A cold rolled sheet was annealed continuously at holding temperature ranging from 580 to 760 ℃. The microstructures were analyzed in detail based on contiuous cooling transformation（ CCT） curves that were simulated with JM artP ro softw are. The results show ed that recrystallization and perlitic transformations caused a diversity of microstructures and mechanical properties. In comparison with annealed steel that was produced from insufficient recrystallization,annealed steel produced from sufficient recrystallization had more isometric grains and exhibited low er strength and higher ductility. Higher annealing temperatures than A_1 provided steel with lamellar pearlite zones,large ferrite grains,low strength,and high ductility. The results are attributed to the property optimization of the steel.

Influence of the Annealing Temperature on the Thickness and Roughness of La<SUB>2</SUB>Ti<SUB>2</SUB>O<SUB>7</SUB>Thin Films

In this work, the impact of the substrate annealing temperature on the thickness and roughness of La2Ti2O7 thin films was verified. A group of LTO Thin films was grown on Si (100) substrates successfully via pulsed laser deposition technique (PLD) at various annealing temperatures with a constant numbers of pulses and energy per pulse. Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) were used to investigate the thickness and roughness of the deposited La2Ti2O7 thin films. The average thickness of the thin films was decreased due to the increasing in the annealing temperature linearly;the maximum thickness was found (231 nm) when LTO thin film deposited at 500°C. The root mean square roughness was increased linearly with increasing the substrate Temperatures. The minimum roughness was found (0.254 nm) when LTO deposited at (500°C). From the obtained results, its clear evidence that the annealing temperature has an influence on the thickness and roughness of the LTO thin films.

Photocatalytic degradation evaluation of N–Fe codoped aligned TiO2 nanorods based on the effect of annealing temperature

In this paper,a comparative study on the photocatalytic degradation of the Rhodamine B(Rh B)dye as a model compound using N–Fe codoped Ti O2 nanorods under UV and visible-light(λ≥420 nm)irradiations has been performed.Ti O2 photocatalysts were fabricated as aligned nanorod arrays by liquid-phase deposition process,annealed at different temperatures from 400 to 800℃.The effects of annealing temperature on the phase structure,crystallinity,BET surface area,and resulting photocatalytic activity of N–Fe codoped Ti O2 nanorods were also investigated.The degradation studies confirmed that the nanorods annealed at 600℃composed of both anatase(79%)and rutile phases(21%)and offered the highest activity and stability among the series of nanorods,as it degraded 94.8%and 87.2%Rh B in 120 min irradiation under UV and visible-light,respectively.Above 600℃,the photocatalytic performance of nanorods decreased owning to a phase change,decreased surface area and bandgap,and growth of Ti O2 crystallites induced by the annealing temperature.It is hoped that this work could provide precious information on the design of 1 D catalyst materials with more superior photodegradation properties especially under visible-light for the further industrial applications.

Effects of substrate temperature and annealing treatment on the microstructure and magnetic characteristics of TbDyFe films

A series of TbDyFe films were prepared by DC magnetron sputtering. The effects of substrate temperature and annealing temperature on the phase structure and the magnetic properties of the sample films were investigated. The an-nealing treatment has a significant influence on the microstructure and the magnetic properties of the sample. The results obtained by XRD indicate that the films deposited at a temperature lower than 525℃ are amorphous and have an easy magnetization direction perpendicular to the film plane. An RFe2 phase is formed in the sample annealed at 550℃ and the residual phases observed are Fe and rare earth oxide. The magnetic properties Hc and Mr/Ms of the film annealed at 550℃ obtain the maximum values,for which the formation of the RFe2 phase is mainly responsible. An annealing treatment leads to a rotation of the sample’s easy axis from being parallel to the film surface to becoming vertical.

Effect of Annealing Temperature on the Precipitation Behavior and Texture Evolution in a Warm-Rolled P-Containing Interstitial-Free High Strength Steel

By using transmission electron microscopy and electron back-scattered diffraction, the effect of annealing temperature on the precipitation behavior and texture evolution in a warm-rolled interstitial-free high strength steel was studied. The results indicated that fine FeTiP could precipitate at 650 ℃, and the number of those precipitates increased greatly with the increasing annealing temperature until 800 ℃. Furthermore, the nucleation of FeTiP was influenced by the precipitation of TiC and （Ti, Nb） C. The near absence of FeTiP and a large volume fraction of TiC and （Ti, Nb） C in matrix are envisaged to be primarily responsible for the sharp y-fiber texture. As the boundary pinning effect caused by FeTiP is weak and there are less interstitial C atoms in matrix. Thus, annealing at 800 ℃ leads to the highest intensity of y-fiber texture.

Influences of Annealing Temperature and Doping Concentration on Microstructural and Optical Properties of CeO_2:Sm^(3+) Nanocrystals

Nanocrystals of CeO2 with different doping concentrations of Sm3＋ were synthesized by a novel and cost- effective method. The crystal structure, morphology and particle size were systematically investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Effects of the annealing temperature and doping concentrations on the microstructural properties of the crystals were studied. X-ray diffraction analysis indicates that the cubic structure of the CeO2 is not affected by the doping of Sm3＋ up to a doping concentration of 20%. Different structural parameters such as lattice constant, surface area, bulk density and porosity of the crystal were determined and discussed. Microscopic images of the CeO2：Sm3＋ suggest that the thermal decomposition of oxalate precursor is a suitable synthesis pathway to produce uniform-sized microparticles and nanoparticles. The influences of annealing temPerature and doping concentration of Sm3＋ on the optical properties of the nanocrystals were also discussed. The photoluminescence excitation spectra reveal that the charge transfer band is redshifted with increasing annealing temperatures. Emission attains its maximum intensity for Sm3＋ concentration of 1%, and higher concentrations lead to emission quenching.

Effect of Annealing Temperature on Recrystallization Behavior of Cold Rolled Ti-Microalloyed Steel

In order to develop cold rolled Ti-microalloyed steel strips, the effects of annealing temperature on recrys-tallization behavior of experimental steel were researched by optical microscopy （OM）, transmission electron micros-copy （TEM） and Vickers hardness test. The annealing treatment could be divided into three distinct stages： recovery, recrystallization and grain growth. Reerystallization took place from 933 to 1033 K, during which a large number of recrystallized grains appear and hardness drops sharply. The morphology and size of TiN particles nearly remained unchanged at different stages of processing. With increasing annealing temperature, nanometer precipitates coarsened and the dislocation density was significantly reduced. In comparison with annealing time, annealing temperature was more crucial for recrystallization of cold rolled Ti microalloyed steel. It could be concluded that the pinning force of nanometer particles on dislocations increased the recrystallization temperature. At higher annealing temperature, re crystallization took place because of precipitates coarsening caused by Ostwald ripening.