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In this study, nc-ZnO films deposited in a Pulsed Laser Deposition (PLD) system at various temperatures were used to fabricate high performance transistors. As determined by Transmission Electron Microscope (TEM) images, nc-ZnO films deposited at a temperature range of 25°C to 400°C were made of closely packed nanocolums showing strong orientation. The influences of film growth temperature and post growth annealing on device performance were investigated. Various gate dielectric materials, including SiO₂, Al₂O₃, and HfO₂ were shown to be suitable for high performance device applications. Bottom-gate FETs fabricated on high resistivity (>2000 ohm-cm) Si substrates demonstrated record DC and high speed performance of any thin film transistors. Drain current on/off ratios better than 10¹² and sub-threshold voltage swing values of less than 100mV/decade could be obtained. Devices with 2μm gate lengths produced exceptionally high current densities of >750mA/mm. Shorter gate length devices (LG=1.2μm) had current and power gain cut-off frequencies, f_T and f_max, of 2.9GHz and 10GHz, respectively.

X-ray diffraction patterns of melt-spun Fe-Cu-Nb-Si-B (FINEMET-type) alloys reveal that crystallites of Fe₂Si and Fe₃B phases with average sizes of 15(5) and 20(2) nm are present in the surface layer of thickness ≈ 10 Å and these nanocrystallites occupy 5–10% of the total volume. The results of an elaborate analysis of the high-resolution electrical resistivity data taken in a temperature range from 13 K to 300 K and their discussion in the light of existing theories demonstrates that the enhanced electron–electron interaction (EEI), quantum interference (QI) effects, inelastic electron–phonon scattering, coherent electron–magnon (and/or electron-spin fluctuation) scattering are the main mechanisms that govern the temperature dependence of resistivity. Of all the inelastic scattering processes, inelastic electron–phonon scattering is the most effective mechanism to destroy phase coherence of electron wavefunctions. The physical quantities such as diffusion constant, density of states at the Fermi level and the phase-breaking time, determined for the first time for the alloys in question, exhibit a systematic variation with the copper concentration.

The grain growth kinetics of nanocrystalline copper thin film samples was investigated. The grain size of nanocrystalline copper samples was determined from the broadening of X-ray spectra. It was found that the grain size increased linearly with isothermal annealing time within the first 10 minutes, beyond which power-law growth kinetics is applied. The activation energy for grain growth was determined by constructing an Arrhenius plot, which shows an activation energy of about 21 – 30 kJ/mol. The low activation energy is attributed to the second phase particle drag and the porosity drag, which act as the pinning force for grain growth in nanocrystalline copper.

The preferred (002) orientation Zinc oxide (ZnO) nanocrystalline thin films have been deposited on ITO-coated glass substrates by means of sol-gel spin-coating technology and rapid thermal annealing for use in dye-sensitized solar cells (DSSC). The effects of annealing temperature (400 ~ 700 °C) on the microstructure and morphology of ZnO thin films were studied. With the increase of heating temperature from 400 °C to 700 °C, the grain size of ZnO thin films decreases from 80 to 10 nm. The decreases in grain size of ZnO thin films contributed to the improvement on the absorption of dye onto the films. The ITO/ZnO/RuL₂(NCS)₂ electrodes with high absorption in the wide range containing visible light reveal that the nanoporous structure can adsorb easily the dye and can be expected in the application of DSSC.

NiTi intermetallic with nanocrystalline structure was produced by mechanical alloying of the elemental powders and the effect of subsequent heat treatment was investigated. The products were characterized using X-ray diffraction and microhardness measurements. The results showed that after 60 h of mechanical alloying, disordered B2-NiTi phase can be obtained as a metastable phase at room temperature with grain size of 25 nm, lattice strain and high microhardness of 1.2% and 922 HV, respectively.

After heat treatment, disordered structure transformed to ordered NiTi and a small amount of NiTi2 and Ni3Ti phases. The long range order parameters of nanocrystalline NiTi were obtained to be 0.63 and 0.94 after annealing for 30 and 60 mins respectively. After 30 mins of heat treatment, 81.5% of Ni (or Ti) atoms were on the right sites and after 60 mins it increased to 97%. Grain growth and decrease of microhardness and lattice strain were also observed after heat treatment. After 60 mins of heat treatment the grain size, lattice strain and microhardness of NiTi were 95, 0.09 and 624 HV respectively.

In this research a sol-gel auto-combustion route has been proposed to synthesize nickel-zinc ferrite nanocrystalline powder, using metal nitrates, citric acid as fuel and ammonia as pH adjusting agent. The influence of pH value of the solution on phase evolution, crystallite size and morphology of as-burnt powders were investigated by XRD, SEM and TEM techniques. The results revealed that with pH=7 the single phase nickel-zinc ferrite nanocrystalline powders with crystallite size of about 27nm were formed directly after auto combustion process.

The purpose of experiment was to produce bulk nanocrystalline Zn by mechanical attrition. The bulk nanocrystalline Zn produced by mechanical attrition was studied. The microstructural evolution during cryomilling and subsequent room temperature milling was characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). In this paper, Nanocrystalline Zn was produced by insitu consolidation of Zn elemental powder using mechanical attrition at liquid nitrogen and room temperature. For the samples studied, the longest elongation of 65% and highest stress of 200 MPa is obtained in nanocrystalline Zn during tensile testing at the condition of strain rate (10^-3 sec^-1) and 20°C which is equal to 0.43 T_m (T_m is the melting temperature of pure Zn).

The aim of present research is to study the influence of sintering temperature on the preparation of nanocrystalline Yttrium Iron garnet (YIG) with improved magnetic properties. The nanocrystalline YIG powders were synthesized using Microwave-Hydrothermal (M-H) method. The synthesized powders were characterized using X-ray diffraction (XRD) and Transmission Electron Microscope (TEM). The powders were sintered at various temperatures using microwave sintering method. The sintered samples were characterized using XRD. The complex permeability, dielectric constant and loss tangent of sintered YIG ceramic were also measured and discussed in this paper

Nanocrystalline biphasic calcium phosphate (BCP) powder was synthesized from natural bovine bone via a very economic process. The bovine bone was annealed at 900°C for 2 h and elemental compositions were qualitatively identified by energy dispersive X-ray spectroscopy (EDS) in the scanning electron microscope (SEM). The calcined bovine bone was powdered and mixed with calcium hydrogen phosphate dihydrate (CaHPO₄·2H₂O, DCPD). After that, the prepared powder was uniaxially pressed into pellets. The pellets were annealed at 900–1200°C and then crushed to obtain nanocrystalline BCP powder. The morphology and microstructure of the BCP powder were studied by SEM. The results showed that the prepared powder consisted of small size and highly agglomerated particles. X-ray diffraction method was utilized to characterize the phase formation and crystallite size of prepared powder. The crystallite sizes of BCP powder calculated by using XRD data were in the range of 20–60 nm.

A new magnetorheological (MR) fluid was synthesized by dispersing Fe₈₄Nb₃V₄B₉ nanocrystalline powders in a nonvolatile ionic liquid (N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium tetrafluoroborate), which is stable from 282K to 573K. The structure, morphology, and magnetization of Fe₈₄Nb₃V₄B₉ nanocrystalline powders prepared by mechanical alloying were analyzed by using an X-ray diffractometer (XRD), a vibrating sample magnetometer (VSM), and a scanning electron microscopy (SEM), respectively. The magnetic clusters of the synthesized MR fluid were observed by using a digital microscope, and its MR properties were measured by using a cone-plate type viscometer. The experimental results showed that Fe₈₄Nb₃V₄B₉ nanocrystalline powders with an average grain size of 10–20 nm can be prepared by mechanical alloying. The MR fluid is magnetic-field-responsive, behaves like non-Newtonian fluids, and its magnetorheological properties are influenced by the applied magnetic flux density and the width of magnetic clusters.

Specimens of nanocrystalline pure gold were prepared by the gas deposition method. The formation of helium bubbles in the specimens and their annealing behavior were studied in order to confirm their effect on thermal stabilities of grain size and mechanical properties. The specimens with 10-25nm mean grain size were analyzed by transmission electron microscopy and X-ray diffraction methods. Spherical helium bubbles, about 5nm in diameter, were formed, the same as in the case of helium ion implantation. After annealing at 573K for 1h in vacuum, most of the bubbles had not disappeared and some were trapped at the grain boundaries. Larger numbers of bubbles were trapped at grain boundaries in the specimens with high thermal stability than for low thermal stability specimens. Helium bubbles trapped at grain boundaries can be considered as local barriers to grain growth and to contribute to thermal stability of mechanical properties.

TiO₂ sol-gel thin films were deposited on glass substrates by dip coating method. Nanocrystalline TiO₂ thin films were prepared at 300°C. The effect of annealing temperature on optical properties of nanocrystalline TiO₂ thin films was studied. The films were characterized by different techniques: XRD, UV-visible spectroscopy, FTIR spectroscopy and FESEM. The characterization studies revealed that the films are crystallized as anatase phase and are nano-structured. The optical measurements were showed the indirect band gap between 3.31 and 3.35 eV with corresponding crystallite sizes between 8.9 and 3.7 nm at the temperatures 300, 400 and 500°C. The FESEM images of film were showed spherical nanocrystalline structure of TiO₂ particles with the crystallite sizes between 30 and 100 nm. It is also observed that refractive index of the film increases with increasing the annealing temperature. The smaller crystallite size gives larger band gap due to quantum size effects.

The indentation simulation of the nanocrystalline Ni is carried out by molecular dynamics technique (MD) to study the mechanical behavior at nanometer scales. The sphere indenter is used, and simulation sample with three grains and two grain boundaries is adopted. The strength of nanocrystalline is studied as indenter is set at grain boundary and grain, respectively. Some defects such as dislocations or slipping deformation are observed. It is found that dislocations are emitted from the grain boundary or the sample surface. The temperature distribution of local region around indenter is analyzed and it can explain our MD simulation results.

Al–7% Si alloys were prepared by ball milling technique under different milling time. The effect of milling time on the microstructure and mechanical properties were studied. The results indicate that the grain size decrease with increasing the milling time, the average dislocation density, ρ, was found to exhibit a drastic increase by increasing the milling time, the median diameter, μ decreases, while the value of width parameter, σ is approximately constant with increasing the milling time. The value of Vickers hardness (HV) increases by increasing milling time, this increase was attributed to the refinement of grains with increasing milling time.

In this paper, we studied the grain size and volume fraction change of $\alpha$-Fe(Si) nanocrystalline phase as a function of Cu, Mo and Si content in Fe${}_{74.5-x}$Cu${}_x$Mo₃Si${}_{13.5}$B₉, Fe${}_{76.5-y}$Cu₁Mo${}_y$Si${}_{13.5}$B₉, Fe${}_{73.5}$Cu₁Mo₃Si${}_z$B${}_{22.5-z}$, and also the annealing temperature and time in Fe${}_{73.5}$Cu₁Mo₃Si${}_{13.5}$B₉ alloy. Cu is an element promoting ultrafine structure and crystallization progresses, it causes the grain size of the $\alpha$-Fe(Si) phase to decrease suddenly, the volume fraction of $\alpha$-Fe(Si) phase to increase only by adding 0.5 at.% Cu. Also, Mo causes the grain size of $\alpha$-Fe(Si) phase to decrease like Cu, while suppressing the increase of the volume fraction of $\alpha$-Fe(Si) phase, Si has no little effect on the grain size of $\alpha$-Fe(Si) phase, diffuses into the inner part of $\alpha$-Fe(Si) phase upto Si 13.5 at.%, but suddenly increases grain size above Si 13.5 at.%. The microstructure of Fe${}_{73.5}$Cu₁Mo₃Si${}_{13.5}$B₉ alloy is nearly completed at 520${}^{\circ }$C for about 20 min, the grain size is approximately 13.8–14.1 nm, the volume fraction of $\alpha$-Fe(Si) phase is within 61–66%, initial permeability at 1 kHz is within 59,800–61,100.

Nanocrystalline Co-doped ZnO (Zn_1-xCo_xO, x = 0.00, 0.05) powders have been successfully prepared by a microwave-assisted combustion method using Zn(NO₃)₂·6H₂O and Co(NO₃)₂·6H₂O as starting materials and urea as fuel. The as-prepared products were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). It was found that the combustion process took only a few minutes to obtain Zn_1-xCo_xO powders. The field dependence of magnetization measurement at room temperature for the as-prepared Zn_0.95Co_0.05O powders exhibited the obvious ferromagnetic behavior.

Nanocrystalline CeO₂ with different particle sizes has been studied under high pressure using Raman spectroscopy techniques and diamond anvil cell at room temperature. The pressure shift of the first-order Raman frequency for each particle sizes was measured. Linear dependence of the first order Raman frequency on pressure for each particle sizes has been observed. We found that the first order Raman frequency decreases with the decreasing particle sizes under ambient condition and the lattice constant increases with the decreasing particle size. The increasing molar fraction of oxygen vacancies with the decreasing particle size is responsible for the lattice expansion.

The nanoscale deformation field of twin boundary dislocations in nanocrystalline aluminum was experimentally investigated using a combination of high-resolution transmission electron microscopy and geometric phase analysis. The entire strain field of the twin boundary dislocations was mapped and then compared with those of the Peierls–Nabarro and elastic theory dislocation models. The comparison results demonstrated that the Peierls–Nabarro dislocation model best describes the strain field of the twin boundary dislocations in nanocrystalline aluminum.

Ni-W alloy coating is a kind of promising environmental friendly alloy to substitute for hard chrome plating, for its excellent functional properties. Their properties depend mainly on the structure and defect, such as cracks. The crack is catastrophe to both physical and chemical properties and crystalline state also affect their properties and application. In this work, nanocrystalline nickel tungsten alloy (nc Ni-W) coating, amorphous nickel tungsten alloy (a Ni-W) coating and crystalline nickel tungsten alloy (c Ni-W) coating were prepared under ultrasonic direct current (UDC) electroplating. The aim of the present study is to achieve structure control and high surface quality of Ni-W alloy coatings, and investigate corrosion properties of these coatings to explain the contradiction of better corrosion resistance of nc Ni-W coating than a Ni-W coating in experiment and theory. Thus X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) were used to examine the composition, crystalline state, microstructures and defects of the samples. Moreover, potentiodynamic polarization test was used to study the corrosion behavior of electroplated nickel–tungsten alloys.

At room temperature, titanium dioxide (TiO₂) films were deposited by the direct current pulse magnetron sputtering technique. Varying O₂/Ar flow ratio, TiO₂ films with different nanocrystalline structures were obtained. The high resolution transmission electron microscopy results show that with O₂/Ar = 6/14, the nanocrystalline in rutile phase appears in as-deposited film. Then X-ray diffraction patterns of annealed films revealed that with O₂/Ar = 6/14, the higher weight fractions of rutile TiO₂ appear in films. The optical emission spectroscopy results show that with O₂/Ar < 6/14, O element was mainly existed as O^-/O⁺ ions, instead of excited state of O atoms.