Search

Transmission electron microscopy (TEM), high-resolution TEM, and x-ray energy dispersive spectroscopy results showed that Zn metallic nanocrystals and ZnSiO3 insulating nanocrytals embedded in a SiO2 matrix were created from the ZnO thin films deposited on n-Si (001) substrates due to rapid thermal annealing. The formed Zn metallic nanocrystals were transformed into monoclinic ZnSiO3 insulating nanocrystals with increasing number of Zn atoms resulting from an increase in the annealing time up to 10 min. The transformation mechanisms from metallic Zn nanocrystals to insulating ZnSiO3 nanocrystals in a SiO2 matrix due to rapid thermal annealing are described on the basis of the experimental results.

The electrical transport and 1/f conduction noise properties of LaFe1−xNixO3 (x = 0.3, 0.4 and 0.5) thin films have been studied. The temperature dependent resistivity data have been fitted with Mott's variable-range hopping model. From the resistivity data we have estimated various parameters, namely, the hopping distance (Rh), the hopping energy (Eh) and the density of states at the Fermi level (N(EF)). The decrease in the hopping energy and the increase in the density of states at room temperature have been observed with the increase in Ni doping for all samples. The Ni doping increases the density of charge carriers and enhances delocalization induced phenomena in the system. The magnitude of the normalized noise SV/V2 increases with the decrease in the Ni concentration over the whole temperature range. The conduction noise is also proportional to the square of the bias current, which confirms that the noise arises from the conduction fluctuations. The Hooge parameter (γ) calculated at room temperature is compared with its value in semiconductors and manganite/oxide materials. The observed features have been explained on the basis of charge-carrier doping in LaFeO3. The noise measurements in conjugation with the electrical properties of the film propose the propitious characteristic of the system.

The spinel thin films of LiSnx∕2Mn2−xO4 prepared by pulsed laser deposition were studied in regards with electrochemical reversibility and discharge capacity. LiSn0.0125Mn1.975O4 thin films possessed a large capacity of ∼120mAhg−1 and a high capacity retention of >81% relative to their initial capacity at 4C after the 90th cycle. Such promising results are believed to originate from the Mn4+-richer spinel structure and the less distortion of MnO6 octahedra. The near-edge x-ray-absorption fine structure result of the cycled LiSn0.0125Mn1.975O4 films can be highlighted with the specific local t2g symmetry resulting from the interaction between Mn 3d and O 2p.

Copper-doped p-ZnO thin films (Cu:ZnO) were grown on α-Al2O3(0 0 0 1) and 6H:SiC(0 0 0 1) single crystal substrates by plasma-assisted molecular beam epitaxy. A p–n hetero-junction with p-Cu:ZnO/n-6H:SiC was successfully fabricated and demonstrated as a greenish-blue light emitting diode (LED). The rectifying I–V curve along with the matching photoluminescence and electroluminescence emissions characterizes the fabricated p–n hetero-junction LED. The Cu cell temperature (TCu) and the post-deposition annealing environment greatly influence the Cu oxidation state, and hence the electrical conversion from n-type to p-type and carrier concentration in the films. The higher TCu and post-annealing in O-plasma were observed to be the favorable conditions for Cu2+ and hence the p-type nature of the films.

We present here the magnetic, dielectric, and electronic structural properties of Ti doped BiMn2O5 multiferroic materials. The x-ray diffraction (XRD) studies of BiMn2−xTixO5 (0≤x≤0.5) indicate no structural change up to x=0.5, though the lattice parameters (a and c) increase with increasing value of x. Dielectric constant and magnetization data show the evolution of new dielectric anomalies at ∼120 K and weak magnetic feature at ∼86 K with the Ti substitution compared to that of undoped one. However, Ti replacement vanishes the ferroelectric transition of BiMn2O5 at ∼35 K and gradually suppresses the antiferromagnetic ordering at ∼39 K. Polarization of Bi 6s2 lone pair electrons is attributed to the reason behind new dielectric anomalies, whereas new weak magnetic feature at ∼86 K is attributed to strong spin-phonon coupling. X-ray absorption spectroscopy (XAS) studies on O K, Mn K, L3,2, and Ti L3,2 edges of BiMn2−xTixO5 samples along with the reference compounds have been performed and compared to best...

Transmission electron microscopy (TEM), high-resolution TEM, and atomic force microscopy images showed that the columnar structure and the surface morphology of grains in ZnO thin films grown on p-InP substrates were changed due to thermal treatment. The surface morphology variation of the ZnO thin films was attributed to the curvature modification of the subpopulations consisting of ZnO grains. While the top surface of the ZnO grains became parallel with the {0001} planes due to thermal treatment, the curvature of the subpopulations in the ZnO grains became rough. Evolution mechanisms of the surface morphology of ZnO thin films are described.

We report the room temperature ferromagnetism and a metal–semiconductor transition at 227 K in 200 MeV Ag15+-ion irradiated thin films of Fe-implanted ZnO. The single phase nature of Fe-doped ZnO after ion irradiation is confirmed by x-ray diffraction. Magneto-resistance measurements show spin polarization below 150 K. X-ray absorption spectroscopy and x-ray magnetic circular dichroism studies at room temperature reveal that Fe is oxidized in a mixed valence (Fe2+ and Fe3+) state and the magnetic signal is due to the Fe2+ state. The observations are explained on the basis of the combined effect of carrier doping by Fe3+ and oxygen vacancies.

This work reports the formation of Ni nanostructures, their growth and saturation to form oxides by using ion implantation and thermal treatment in air at 600 °C. A quartz (SiO2) matrix was implanted with 100 keV Ni+ ions to doses in the range 5 × 1015–2 × 1017 ions cm−2. The formation of Ni nanoclusters was observed by high resolution x-ray diffraction (HRXRD), UV–visible optical spectroscopy, dc magnetization, AFM/MFM and x-ray absorption spectroscopy (XAS). The cluster size distribution is narrow, with an average size of ~25 ± 0.5 nm for the sample implanted at a dose of 1 × 1016 ions cm−2, but increases with implantation dose. Optical absorption spectra also show a clear signature of a surface plasmon resonance (SPR) peak at around 388 nm in accordance with the theoretical Mie's spectra. Temperature dependent zero-field-cooled and field-cooled magnetization measurements clearly indicate a superparamagnetic behavior, which is properly analyzed considering the size distribution of the magnetic nanostructures. The results show that the magnetic properties of the nanoparticles can be controlled by the implantation dose. A detailed investigation of the local structure using Ni K-edge NEXAFS/EXAFS suggests that the size of the Ni nanostructures is altered by implantation dose, reaching saturation in the form of oxides/silicates of Ni at a dose of 2 × 1017 ions cm−2.

High-resolution transmission electron microscopy (HRTEM) images, selected-area electron diffraction (SAED) patterns, and energy dispersive x-ray spectroscopy (EDS) profiles showed that P atoms accumulated due to thermal treatment on the top sides and in the heterointerface layers of ZnO thin films grown on p‐InP (100) substrates, resulting in the formation of amorphous ZnO layers in the ZnO thin films. The formation mechanisms of the ZnO amorphous layers due to thermal treatment are described on the basis of the HRTEM, the SAED, and the EDS measurements.

The x-ray diffraction patterns, transmission electron microscopy images, and selected-area electron diffraction patterns for the ZnO∕Si heterostructures annealed at 900°C showed that orthorhombic ZnSiO3 nanoparticles were formed in the amorphous layer between the ZnO film and the Si substrate, resulting from the interdiffusion between the ZnO film and the Si substrate due to thermal treatment. Auger electron spectroscopy depth profiles for the ZnO∕Si heterostructures annealed at 900°C demonstrated the formation of amorphous Zn2xSi1−xO2, an interfacial layer. A formation mechanism for the orthorhombic ZnSiO3 nanoparticles embedded in the amorphous Zn2xSi1−xO2 layer is described on the basis of the experimental results.

Electrical fluctuation, magnetic, and magneto-transport properties of the (111) oriented Fe3O4 thin film deposited by pulsed laser deposition on technologically important silicon substrate have been studied. Low frequency conduction noise follows the trend of resistivity behavior with respect to temperature and the normalized value of noise drops by two orders of magnitude below the Verwey transition. At room temperature, magnetoresistance of the film is 5% at 8T. X-ray magnetic circular dichroism measurements performed on 10nm thick film of Fe3O4 indicate a single crystal-like uniform distribution of Fe ions in its crystal or magnetic structure.

The bistable effects of CdSe/ZnS nanoparticles embedded in a conducting poly N-vinylcarbazole (PVK) polymer layer by using flexible poly-vinylidene difluoride (PVDF) and polyethylene terephthalate (PET) substrates were investigated. Transmission electron microscopy (TEM) images revealed that CdSe/ZnS nanoparticles were formed inside the PVK polymer layer. Current-voltage (I-V) measurement on the Al/[CdSe/ZnS nanoparticles+ PVK]/ITO/PVDF and Al/[CdSe/ZnS nanoparticles+ PVK ]/ITO/PET structures at 300 K showed a nonvolatile electrical bistability behavior with a flat-band voltage shift due to the existence of the CdSe/ZnS nanoparticles, indicative of trapping, storing and emission of charges in the electronic states of the CdSe nanoparticles. A bistable behavior for the fabricated organic bistable device (OBD) structures is described on the basis of the I-V results. These results indicate that OBDs fabricated by embedding inorganic CdSe/ZnS nanoparticles in a conducting polymer matrix on flexible substrates are prospects for potential applications in flexible nonvolatile flash memory devices.

For the new combination of audio and display devices on flexible polymer substrate, we present the audible OLED device on piezoelectric polyvinylidene difluoride (PVDF) with ITO electrode prepared by roll to roll sputter coating and laser ablation pattern technique. Our flexible audible display (FAD) device showed the luminescence as well as the sound generating functions under the structural schematics with two device characteristics sharing the one flexible polymer substrate for the next generation “superposed” electronic devices.

We present structural, electrical transport, magnetic, and electronic structure studies of Mg0.95Mn0.05Fe2−2xTi2xO4 ferrite using x-ray diffraction, dielectric spectroscopy, DC magnetization and near edge x-ray absorption fine structure (NEXAFS) measurements. The x-ray diffraction study shows a structural transition from cubic to tetragonal with Ti substitution. The dielectric constant and DC conductivity increase with Ti substitution up to x = 0.2. However, with further increase of substitution both the dielectric constant and DC conductivity decrease. This electrical behavior indicates that at low values of substitution, hopping between Fe3+ and Fe2+ increases whereas at higher concentrations the total content of Fe ions decreases. It is observed that all the samples exhibit ferrimagnetic behavior at 300 K and the saturation magnetization decreases with increase in Ti substitution. The NEXAFS measurements have been carried out at O K-, Fe L-, Fe K-, and Ti L-edges to investigate the chemical states and the electronic structure of the Mg0.95Mn0.05Fe2−2xTi2xO4 (0≤x≤0.5) system at room temperature. The O K-edge spectra indicate that the Fe 3d orbitals are considerably modified with the substitution of Ti ions. At x≥0.3, a new spectral feature appears (~532 eV) due to the transitions from oxygen 2p to Ti 3d orbitals which starts dominating the pre-edge spectra of the system. Both Fe L3,2- and Fe K-edge spectra indicate that iron Fe3+ ions convert into Fe2+ with the substitution of Ti ions. The Ti L3,2-edge NEXAFS spectra reveal that the Ti remains in the 4+ state for all the samples. The observed experimental results have been explained on the basis of dilution of the magnetic sublattice by Ti substitution, which provides a strong interplay between electrical and magnetic properties along with their electronic structure.

High quality gallium doped ZnO (Ga:ZnO) thin films were grown on c‐Al2O3(1000) by plasma-assisted molecular beam epitaxy, and Ga concentration NGa was controlled in the range of 1×1018–2.5×1020∕cm3 by adjusting∕changing the Ga cell temperature. From the low-temperature photoluminescence at 10K, the donor bound exciton I8 related to Ga impurity was clearly observed and confirmed by comparing the calculated activation energy of 16.8meV of the emission peak intensity with the known localization energy, 16.1meV. Observed asymmetric broadening with a long tail on the lower energy side in the photoluminescence (PL) emission line shape could be fitted by the Stark effect and the compensation ratio was approximately 14–17% at NGa⩾1×1020∕cm3. The measured broadening of photoluminescence PL emission is in good agreement with the total thermal broadening and potential fluctuations caused by random distribution of impurity at NGa lower than the Mott critical density.

We report the x-ray absorption studies on O K, Fe L3,2, Ni L3,2, and Pr M5,4 edges in PrFe1−xNixO3 along with their structural, electrical transport, and magnetization characterizations. All the samples are in single phase having orthorhombic structure with space group Pnma for x⩽0.4. Ni doping at Fe site brings the system in the conducting regime, resistivity decreases from GΩcmto260mΩcm at room temperature, and the magnetic ordering is stabilized. The temperature dependent resistivity follows the semiconducting behavior and fits well with Greaves’ variable range hopping model. The gap parameter is reduced from 2to0.118eV. The materials are in weak ferromagnetic state and magnetization is gradually decreasing with the enhancement of Ni substitution, whereas magnetic anisotropy is reduced substantially. A new feature about 2.0eV lower than the pre-edge of PrFeO3 in O K edge is observed with Ni substitution at Fe site due to the 3d contraction effect and is growing with the increase of Ni substitution. Fro...

Indium tin oxide, which is used as transparent conducting layer in flexible device, is deposited on PET film by a magnetron sputtering in 300 mm wide roll-to-roll process (vacuum web coating). Sheet resistance, specific resistance and transmittance is differed by sputtering parameters such as working pressures, oxygen partial pressure, and thickness of ITO layer. ITO layer is deposited about 90 nm at roll speed of 0.24 m/min and its sputtering power is 3 kW. From the XRD spectrum deposited ITO layer is verified as amorphous. Under working pressure varied from to , sheet resistance is lowest at the working pressure of and its value is from to at the thickness of 90 nm. Oxygen partial pressure also varies sheet resistance and is optimized at the regime from 0.2% () to 0.6% (). In this oxygen partial pressure sheet resistance is lower than . As ITO layer thickness increases, sheet resistance decreases down to and specific resistance is about in 340 nm thickness ITO layer. Transmittance is measured at the wavelength of 550 nm and is about 90% for 180 nm thickness ITO/PET.

The plane-view high-resolution transmission electron microscopy (HRTEM) images in ZnO thin films grown on p-Si substrates showed that (101¯0) asymmetric grain boundaries with a periodic array of strain contrast features existed in a sparse columnar structure for as-grown ZnO thin films and that (112¯0) asymmetric grain boundaries and (8513¯0) symmetric grain boundaries existed in a dense columnar structure for annealed ZnO thin films. The atomic arrangement variations of [0001]-tilt grain boundaries in ZnO thin films grown on Si substrates due to thermal treatment are described on the basis of the HRTEM results.

Electron-beam-induced Zn nanocrystal islands were formed in a dielectric SiO2 layer. When a ZnO thin film on a p-type Si with amorphous SiOx interface layer is subjected to a 900°C annealing followed by electron irradiation in a transmission electron microscope environment, an amorphous Zn2xSi1−xO2 layer is formed. Upon irradiation with a 300keV electrons, metallic and single crystal nanoislands of Zn with ∼7–10nm diameter were formed and embedded within the SiO2 interface layer. Possible mechanisms for the formation of Zn nanocrystals are presented.

ZnO thin films were grown on n-Si (001) substrates by using plasma-assisted molecular beam epitaxy. A cross-sectional bright-field transmission electron microscopy (TEM) image showed that small ZnO columnar grains were embedded into large columnar grains, and a selected-area electron diffraction pattern, and an x-ray diffraction pattern showed that the ZnO thin film were nearly c-axis oriented. The evolution of the ZnO columnar structure was analyzed by using the evolution of the strain due to the interaction of the columnar grains, as observed by using high-resolution TEM. The initial formation mechanisms of the supersaturation region and the columnar grains are described.

We present the results of TiNiTiAu multilayer ohmic contacts on n -type 6H-SiC and their interface analysis. The as-deposited contacts show rectifying behavior and, with the increase in annealing temperature, they gradually transform to high-quality ohmic contacts exhibiting linear current-voltage characteristics. The interface evolution was analyzed through glancing angle X-ray diffraction, Auger electron spectroscopy, and atomic force microscopy. The Ti Si2 and Ni2 Si formed at the interfaces during the low-temperature annealing initiate the conversion from Schottky to ohmic behavior, while the increased Ni2 Si formation at high-temperature annealing makes the perfect ohmic contacts. The results were interpreted through the thermodynamic reaction mechanisms. © 2007 The Electrochemical Society.

Structural, electrical resistivity, and magnetization properties of 200-MeV Ag+15-ion-irradiated Co-implanted ZnO thin films are presented. The structural studies show the presence of Co clusters whose size is found to increase with increase of Co implantation. The implanted films were irradiated with 200-MeV Ag+15 ions to fluence of 1×1012ions∕cm2. The Co clusters on irradiation dissolve in the ZnO matrix. The electrical resistivity of the irradiated samples is lowered to half. The magnetization hysteresis measurements show ferromagnetic behavior at 300K, and the coercive field increases with the Co implantation. The ferromagnetism at room temperature is confirmed by magnetic force microscopy measurements. The results are explained on the basis of the close interplay between the electrical and the magnetic properties.

Low temperature photoluminescence and optical absorption studies on 200MeV Ag+15 ion irradiated Co-implanted ZnO thin films were studied. The Co clusters present in as implanted samples were observed to be dissolved using 200MeV Ag+15 ion irradiation with a fluence of 1×1012ions∕cm2. The photoluminescence spectrum of pure ZnO thin film was characterized by the I4 peak due to the neutral donor bound excitons and the broad green emission. The Co-doped ZnO films show three sharp levels and two shoulders corresponding to 3t2g and 2eg levels of crystal field splitted Co d orbitals, respectively. The ultraviolet-visible absorption spectroscopy also shows the systematic variation of band gap after 200MeV Ag+15 ion irradiation.

Luminescence properties of ZnO films, which have been epitaxially grown on c-sapphire (0001) substrates by plasma-assisted molecular beam epitaxy, are investigated by means of different excitation sources and their measurement conditions. With the increase of measurement temperature, photoluminescence spectra clearly present, the appearance of different bound-exciton peaks (I10 line) with an abrupt increase of emission intensity at the measurement temperature of 30-50K. Hypothetical explanations on the basis of thermalization effects, vibronic/rotational resonance states, and the involvement of the B-valence level in emission are given. In cathodoluminescence (CL), the deep level emission intensity was enlarged with the electron beam penetration depth due to the higher defect density near the interface between ZnO and the sapphire. From the CL image of the ZnO film, the dislocation density was estimated as 6×108-3×109∕cm2. The lasing phenomenon was observed at the threshold power density of 1.3MW∕cm2 at 300K.

ZnO nanoblades and nanoflowers are synthesized using zinc acetate dihydrate Zn(CH3COO)2∙2H2O dissolved in distilled water by ultrasonic pyrolysis at 380–500°C. Thermogravimetry-differential scanning calorimetry, x-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, and low-temperature photoluminescence (PL) were used to characterize the thermal properties, crystalline and optical features of the ZnO nanostructures. The results showed that at 400°C the formation of nanoblades resulted from the simultaneous precipitation and nucleation in zinc acetate precursor. At an elevated temperature of 450°C, decomposition was almost advanced and thus the size of nanopetal became smaller and aggregates became larger by as much as 60nm. The formation of aggregates is explained in terms of random nucleation model. Through PL measurement, nanoblade showed a strong near band-edge emission with negligible deep-level emission and free exciton band-gap energy Eg(0)=3.372eV and Debye temperature β=477±65K by the fitting curve of free exciton peak as a function of temperature to Varshni equation, Eg(T)=Eg(0)−αT2∕(β+T), which are very close to bulk ZnO.

The physical properties of HfO2/HfSixOy stacked gate dielectric films deposited on compressively strained-Si0.74Ge0.26/Si heterolayers have been investigated using Rutherford backscattering spectrometry, high-resolution transmission electron microscopy, time-of-flight secondary ion mass spectroscopy, and Auger electron spectroscopy measurements. Polycrystalline HfO2 film with physical thickness of ∼4.0 nm and an amorphous interfacial layer with a physical thickness of ∼4.5 nm has been observed. Secondary ion mass spectroscopy and Auger electron spectroscopy analyses show the formation of an amorphous Hf-silicate interfacial layer between the oxide deposited and SiGe films. The electrical properties in terms of capacitance–voltage (C–V), conductance–voltage, hysteresis, current density-electric field, and shift in gate voltage under constant current stress have been studied using a metal–oxide–semiconductor structure. Dielectric constants of 26 for HfO2 and 8.0 for the interfacial Hf-silicate layer have be...

A Kaufman‐type 5 cm convex gridded ion‐beam source is characterized in terms of angle‐resolved ion‐beam current density and beam uniformity at various discharge currents, electromagnet currents, and acceleration potentials.

II-Ⅵ ZnO compound semiconductor thin films were grown on -AlO(0001) single crystal substrate by radical beam assisted molecular beam epitaxy and the optical properties were investigated. Zn(6N) was evaporated using Knudsen cell and O radical was assisted at the partial pressure of 110 Torr and radical beam source of 250-450 W RF power. In -2 x-ray diffraction analysis, ZnO thin film with 500 nm thickness showed only ZnO(0002)and ZnO(0004) peaks is believed to be well grown along c-axis orientation. Photoluminescence (PL) measurement using He-Cd (

Al-doped zinc oxide (AZO) thin films have been grown on Al 2 O 3 (0001) substrate by radio-frequency (rf) magnetron sputtering at 550°C. The AZO films have been annealed by a rapid thermal process in H 2 exposure with a temperature range of 600-1000°C. Effects of hydrogen on the AZO films have been investigated using photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The as-grown AZO film shows only broad deep defect-level PL. After annealing at 600°C, deep defect-level emission is quenched and near-band-edge (NBE) emission is observed at around 382 nm (3.2 eV), which can be explained by the H 2 passivation effect. At elevated temperature, two interesting peaks corresponding to violet (406 nm, 3.05 eV) and blue (436 nm, 2.84 eV) emissions have been observed for the first time in annealed AZO thin films. Incorporation of hydrogen and formation of oxygen deficient in annealed AZO films have been studied using XPS. Surface morphology and microstructure of AZO films have been carried out by SEM.

We have investigated Ti/Au (30/50 nm) ohmic contacts to n-ZnO:Al. The samples are annealed at temperatures of 300 and 500°C for 60 s in a flowing N 2 atmosphere. Current-voltage measurements show that the as-deposited sample is ohmic with a specific contact resistance of 2 × 10 2 Ω cm 2 . However, annealing of the sample at 300°C results in much better ohmic behavior with a contact resistance of 2 × 10 4 Ω cm 2 . Further increase in annealing temperature (500°C) causes the degradation of the ohmic property. Glancing angle X-ray diffraction and Auger electron spectroscopy are used to investigate interfacial reactions between the Ti/Au and ZnO layers. It is shown that both rutile and srilankite TiO 2 phases are formed in the as-deposited and annealed samples. It is further shown that annealing at 500°C results in the formation of new phases such as Ti 3 Au and TiAu 2 . A possible explanation is given to describe the annealing temperature dependence of the specific contact resistance.

The dry etching characteristics of ZnO using an inductively couple plasma (ICP) have been investigated, for the first time, as functions of plasma chemistry, radio frequency (rf) table power, and ICP power. The CH 4 /H 2 etchant gases resulted in the highest etch rate of ZnO, suggesting that the etching of Zn in ZnO largely involves a process in which a volatile metallorganic zinc compound, such as Zn(CH 3 ) y is formed. The etch rate was increased with increasing rf table power, and the highest etch rate of 2000 A/min was achieved at an rf table power of 200 W (dc bias: -80 V). As the ICP power was increased, the etch rate also increased, which suggests that the plasma density is also an important factor in this process. Furthermore, it was observed that hydrogen-containing plasma etching enhances the band-edge photoluminescence of the ZnO film.

Perovskite manganite La–Ca–Mn–O (LCMO) thin films were deposited on LaAlO3 (001) single crystal substrate by radio-frequency magnetron sputtering at room temperature. After annealing at 800–1000°C in O2 atmosphere for 1 h, sheet resistance (R) of the LCMO thin films was measured by van der Pauw method in the range of 77–300 K. The characteristic resistance-temperature curves of all the annealed films showed typical insulator to metal transition behavior of colossal magnetoresistance (CMR) materials on cooling. The sheet resistance of LCMO films changes with temperature, conforming to a function of exp (βT) in the temperature range from 77 K to 230 K, which is applicable to an oxide thin film thermistor.

In the present paper the possibility of application of the regularization method for reliable determination of the position and form of structural features of electron energy distribution is considered. The regularization method is used in the processing of the probe characteristics, measured in gas discharge chambers of broad beam gridded Xe ion sources, with peripheral and with divergent magnetic fields, as well as in an ion accelerator with closed electron drift. Electron energy distribution functions with secondary maxima are observed in the plasma devices.

High-quality ZnO film and highly wettable polymethylmethacrylate (PMMA) are obtained by using a keV ion beam. ZnO films are grown on glass substrates by ion beam sputter deposition, changing the oxygen/argon gas ratio, ion beam energy, and substrate temperature. Physical properties of ZnO films were investigated by X-ray diffraction, Rutherford backscattering spectroscopy, and the Van der Pauw method. All the films show a strong preferred orientation along the c-axis. The electrical resistivity is varied from 10-3 to 106 Ωcm and its dependence on the deposition parameters is discussed. The PMMA surface was modified by the ion-assisted reaction technique. Ion dose, ion energy, and oxygen gas flow rate are varied from 5×1015 to 1×1017 ions/cm2, from 0.6 to1.2 kV, and from 0 to 8 ml/min, respectively. A highly wettable PMMA surface can be obtained by irradiating oxygen ions in an oxygen gas environment. X-ray photoelectron spectroscopic analysis shows that hydrophilic groups are formed on the surface of PMMA.

A surface of polytetrafluoroethylene (PTFE) was modified with changing ion doses by 1 keV Ar+ ion irradiation and Cu films with a 5000 A were deposited on the modified PTFE. The scanning electron microscopy study showed that the surface texture of modified PTFE was in the form of filaments whose height increased depending on ion doses. Through x-ray photoelectron spectroscopy spectra, it was found that the intensity of F 1s peaks decreased with ion doses by preferential sputtering of F atoms and the C–C and/or C–F chains were formed by the crosslinking in the newly unstable chains. Cu films were deposited uniformly along the filaments formed on the modified PTFE. In x-ray diffraction spectra of deposited Cu films on modified PTFE, a preferred orientation along (111) and (200) planes was found and a relative intensity of (111)/(200) orientation increased as surface roughness of modified PTFE increased. The resistivity of Cu films was changed from 2.7 μΩ cm of unmodified PTFE to 4.3 μΩ cm of modified PTFE at an ion dose of 1×1016/cm2 and the abrupt increase of resistivity in the modified PTFE at an ion dose of 1×1017/cm2 was due to being cut off the film which resulted from the increased surface roughness.

Tin oxide ( SnO x ) thin films were deposited by ion-assisted deposition (IAD) at various ion beam voltages (V I) onto amorphous SiO2/Si substrate at room temperature. Tin oxide thin films with nonstoichiometric/stoichiometric composition were fabricated. The as-deposited SnO x films were mostly amorphous, but they exhibited various degrees of crystallinity and fine grain size after annealing at 500° C for 1 h in air. The annealed film deposited using an ion beam energy (E I) of 300 eV showed a preferred orientation along the SnO2 (110) plane. The preferred orientation changed to SnO2 (002) for film 1000 (the annealed film deposited with E I=1000 eV) through an amorphous intermediate structure of film 500 (the annealed film deposited with E I=500 eV). X-ray photoelectron spectroscopy study showed that the main Sn3d peaks in all samples were similar to the binding energy of Sn4+ and the atomic ratios for all the films were higher than 1.51. For the film grown under an average energy of 123 eV/atom, the refractive index was 2.0 and the estimated porosity was 5.2% smaller than that of the other films.

In order to accurately determine the oxidation state of tin and to investigate the chemical shifts between tin and its oxides, quantitative Auger electron spectroscopy and X-ray photoelectron spectroscopy studies were performed using Sn metal, stoichiometric SnO2 powder, and polycrystalline SnO x thin films. Films with different oxygen contents were grown using a reactive ion-assisted deposition technique. As the atomic ratio of tin to oxygen in the deposited films increased to the stoichiometric value of 2, the tin M 4 N 4,5 N 4,5 Auger transition and the corresponding Sn 3d 5/2 core-level photoelectron line gradually shifted to lower kinetic energy and higher binding energy by as much as 6±1 eV and 2.39±0.02 eV, respectively, relative to those of the tin metal. An explanation for the observed systematic difference between the chemical shifts of Auger and photoelectron lines is given. It is based on the difference in electronic polarization energy between the final two-hole state produced by the Auger electron emission and the final single-hole state produced by the photoelectron emission.