Zn Ion Implantation Research Articles

Effect of Cu, Zn and Ag Ion Implantation on the Surface Modification of Bacterial Cellulose Films

The paper presents the preliminary results of cellulose modification by ion implantation. Three types of ions were implanted, i.e., copper, zinc and silver with fluences of 5 × 1014 and 5 × 1015 cm−2, respectively. The acceleration voltage of the implanted ions was 30 kV. The ion penetration depth profiles showed differences, especially in the Cu and Ag cases, due to the different ion beams of these elements. The implantation of cellulose with ions clearly changed the wettability of the material surface in the direction of hydrophobicity. The impact of implantation on the growth of the cellulose surface by mold fungi was also noticeable. Only the silver ion implantation had a negative effect on the growth of the Trichoderma viride fungus but did not cause a complete inhibition of growth. Cellulose implantation with Cu and Zn ions clearly stimulated the growth of fungi on the surface of the polymer.

Influence of Annealing on the Dielectric Properties of Zn-SiO2/Si Nanocomposites Obtained in "Hot" Implantation Conditions.

This paper presents the results of AC electrical measurements of Zn-SiO2/Si nanocomposites obtained by ion implantation. Implantation of Zn ions was carried out into thermally oxidized p-type silicon substrates with energy of 150 keV and fluence of 7.5 × 1016 ion·cm−2 at a temperature of 773 K, and is thus called implantation in “hot” conditions. The samples were annealed in ambient air for 60 min at 973 K. Electrical measurements of Zn-SiO2/Si nanocomposites were carried out before and after annealing. Measurements were performed in the temperature range from 20 K to 375 K. The measurement parameters were the resistance Rp, the capacitance Cp, the phase shift angle θ and the tangent of loss angle tanδ, as a function of the frequency in the range from 50 Hz to 5 MHz. Based on the characteristics σ(f) and the Jonscher power law before and after sample annealing, the values of the exponent s were calculated depending on the measurement temperature. Based on this, the conductivity models were matched. Additionally, the real and imaginary parts of the dielectric permittivity were determined, and on their basis, the polarization mechanisms in the tested material were also determined.

Hollow Covalent Organic Framework Cages with Zn Ion‐Implantation Promoting Photocatalytic H2 Evolution

AbstractAbstract: Covalent organic frameworks (COFs) are emerging as a class of photocatalyst for solar energy utilization. The separation of photogenerated excitons in COFs is crucial for their photocatalytic performance. Herein, we report a strategy to tune the electronic structure of COFs by implanting Zn ions within the framework to facilitate the separation and utilization of the photoinduced charges. Zn ions are incorporated within the shell of hollow COF cages (Zn@H‐TpPa) by a sacrificial template method with a formation of hollow cages. The implantation of Zn ions within the framework results in a redistribution of electron density and an increment of the polarity of the COF, as evidenced by experimental and computational analyses, and thus contributes to the separation and transport of charge carries. The Zn@H‐TpPa shows enhanced photocatalytic H2 production efficiency as compared to TpPa. The results demonstrate a new way to optimize the electronic structure of COFs for photocatalysis.

XAFS Study of Thermally Oxidated Sapphire Implanted with Zinc Ions

The local structure of Zn in Al2O3 is studied by the X-ray absorption fine structure (XAFS) method after the implantation of Zn ions and thermal oxidation, which results in the formation of nanoparticles in sapphire. Based on the data of X-ray absorption near edge spectra (XANES), it can be concluded that Zn atoms interact with oxygen and the Al2O3 substrate. The sapphire sample implanted with Zn ions and annealed in oxygen at 600°C contains zinc in three different states: ZnO, zinc spinel (ganite) ZnAl2O4, and metallic Zn in the form of nanoparticles. Since the fraction of zero-valent zinc is close to 50%, very small Zn metal clusters consisting of the minimum possible number of chemically bonded atoms are expected to be formed. The average number of Zn–Zn bonds for each zinc atom in them slightly exceeds unity, i.e., Zn dimers dominate in the sapphire matrix.

Studying a Silica Film Implanted with Zn and Irradiated with Swift Xe Ions

The effect irradiation with swift heavy Xe ions at an energy of 167 MeV has on the structure and properties of a Zn-implanted SiO2 film is studied. The implantation of Zn ions is found to result in the formation of amorphous zinc nanoparticles around 10 nm in size at a depth near the projective range of zinc ions (Rp ≈ 40 nm) in the SiO2 film. Xe irradiation of the film dampens the exciton recombination–induced peak in the photoluminescence spectrum at a wavelength of 370 nm. It also raises the peak at 430 nm, which is associated with radiation defects. Bombarding the surface of the SiO2 film with Хе ions results in the formation of surface craters surrounded by hillocks, and the emergence of Zn-containing nanoparticles.

Evaluation of lattice displacement and electrical property of Zn-ion implanted GaN by Rutherford backscattering spectrometry

The lattice displacement in Zn-ion implanted GaN single crystal wafer is evaluated by Rutherford backscattering spectrometry using proton beam and Photoluminescence measurements. Zn-ion implantation into GaN single crystal wafer is performed with energies of 300 KeV (ion fluence: 2.32 × 1014cm-2), 500 KeV (3.02 × 1014cm-2) and 700 KeV (4.65 × 1014cm-2) at room temperature. The displacement concentration of Ga and N atoms evaluated from minimum yields along <0 0 0 1> direction are 4.8 × 1021 cm−3 and 3.6 × 1021 cm−3 respectively, for as-implanted GaN and decrease to 2.3 × 1021 cm−3 and 4.7 × 1020 cm−3 by annealing in N2 ambient at 700 °C. The lattice displacement of Ga atoms for as-implanted GaN evaluated from the half-value angle of the channeling dip is 0.094 Å for Zn-implanted GaN and recovers to a value of the thermal vibrational amplitude by annealing. The intensity of Yellow Luminescence (YL) observed at around 530 nm for as-implanted GaN increases significantly compared to un-implanted ones, suggesting that gallium vacancy acceptor and nitrogen vacancy donor as origins of YL are induced by Zn-ion implantation. The YL intensity for annealed GaN is almost same as the one for un-implanted GaN. The sheet resistance is 1.04 × 102cm-2 Ω/sq. for un-implanted, 3.98 × 109cm-2 Ω/sq. for as-implanted, and 3.77cm-2 Ω/sq. for annealed GaN. The high resistance for as-implanted GaN is attributed to gallium vacancy as a compensation center. The low resistance and the decrease of YL intensity after annealing is attributed to both a shallow nitrogen vacancy and the decrease of gallium vacancy.

Enhanced optical linearity and nonlinearity of Nd:YAG crystal embedded with Ag nanoparticles by prior Zn ion implantation

Nonlinear optical properties of nanocomposites exhibit wide nonlinear optical applications, but the nonlinear coefficient is not sufficiently high that it limits the potential application. Thus, we improve the nonlinear optical response of Nd:YAG by dual implantation with Zn and Ag ions to induce the formation of Ag nanoparticles (NPs) in the surface of a crystal. And the structural and optical properties of the NPs embedded in the Nd:YAG have been investigated. The surface plasmon resonance (SPR) absorption of Ag NPs in Nd:YAG crystal shows ~3 times enhancement with a narrower spatial distribution of NPs. Meanwhile, third-order nonlinear coefficients of the crystal embedded with NPs increase to 8 orders of magnitude larger than that of pure Nd:YAG due to the SPR effect. Furthermore, annealing can further modify SPR and nonlinear optical properties owing to improved crystalline structure. The present work provides an alternative route for enhancing the nonlinear optical properties and potential application in optical devices.

Raman monitoring of ZnSe and ZnSxSe1−x nanocrystals formed in SiO2 by ion implantation

Structural and optical properties of SiO2 (600 nm)/Si films successively implanted with two types of ions (Zn and Se) or three types of ions (Zn, Se and S) and afterwards annealed at 900 °C were investigated. RS, PL and TEM methods were used to characterize A2B6 nanocrystals synthesized in SiO2 matrix. The Raman spectra recorded using an excitation with two different laser lines (355 and 473 nm) have shown the formation of ZnSe nanocrystals after a double implantation of Zn and Se ions, while ZnSxSe1−x nanoclusters have been synthesized after a triple implantation of Zn, Se and S ions. Based on Raman spectra recorded with blue and UV excitations, the possible sulfur content (x ≈ 0.4) has been estimated for synthesized ternary alloy. The intensive PL bands for SiO2 films implanted with (Zn, Se, S) and (Zn, Se) were detected in the blue and red spectral ranges, respectively.

Improved cytocompatibility of Mg-1Ca alloy modified by Zn ion implantation and deposition

The Mg-1Ca alloy has been modified by Zn ion implantation and deposition (II&D) using metal vapor vacuum arc plasma source (MEVVA). The surface characteristics, corrosion behavior and cytocompatibility were investigated. The auger electron spectroscopy (AES) results showed that a uniform ZnO layer was formed on the surface of Mg-1Ca alloy. The electrochemical measurements revealed that the corrosion potential has been increased, and a comparable corrosion current density in the simulated body fluid (SBF) was obtained for the Zn-modified Mg-1Ca alloy. The indirect cell viability evaluation and direct cell culture results indicated that the cytocompatibility of MC3T3-E1 cells on the Mg-1Ca alloy was improved by the ZnO layer on the surface.

Quartz modification by Zn ion implantation and swift Xe ion irradiation

The quartz slides were implanted by 64Zn+ ions with dose of 5 × 1016/cm2 and energy of 100 keV. After implantation, the amorphous metallic Zn nanoparticles with an average radius of 3.5 nm were created. The sample surface becomes nonuniform, its roughness is increased and its values rise up to 6 nm compared to virgin state, and the roughness maximum is at a value of about 0.8 nm. The surface is made up of valleys and hillocks which have a round shape with an average diameter about 200 nm. At the center of these hillocks are pores with a depth up to 6 nm and a diameter of about 20 nm. After implantation in UV‐vis diapason, the optical transmission decreases while PL peak (apparently due to oxygen deficient centers) at wavelength of 400 nm increases. Then the samples were subjected to swift Xe ion irradiation with the fluences of 1 × 1012–7.5 × 1014/cm2 and energy of 167 MeV. After Xe irradiation, the sample surface roughness shat down to values of 0.5 nm and the roughness maximum is at a value of about 0.1 nm. Optical transmission in UV‐vis diapason increases. The PL peak at wavelength of 400 nm is decreased while a PL peak at wavelength of 660 nm is raised. This peak is presumably due to non‐bridging oxygen hole centers or/and NPs with structure Si(core)/SiO2(shell).HRTEM image of Zn‐implanted quartz subsurface layer. One can see the Zn amorphous nanoparticles, which confirms the electron diffraction pattern (insert).

Surface and local electronic structure modification of MgO film using Zn and Fe ion implantation

Present work is motivated to investigate the surface and local electronic structure modifications of MgO films implanted with Zn and Fe ions. MgO film was deposited using radio frequency sputtering method. Atomic force microscopy measurements exhibit morphological changes associated with implantation. Implantation of Fe and Zn ions leads to the reduction of co-ordination geometry of Mg2+ ions in host lattice. The effect is dominant at bulk of film rather than surface as the large concentration of implanted ions resides inside bulk. Moreover, the evidences of interaction among implanted ions and oxygen are not being observed using near edge fine structure measurements.

Improvement of in vitro corrosion and cytocompatibility of biodegradable Fe surface modified by Zn ion implantation

Pure Fe was surface-modified by Zn ion implantation to improve the biodegradable behavior and cytocompatibility. Surface topography, chemical composition, corrosion resistance and cytocompatibility were investigated. Atomic force microscopy, auger electron spectroscopy and X-ray photoelectron spectroscopy results showed that Zn was implanted into the surface of pure Fe in the depth of 40–60nm and Fe2O3/ZnO oxides were formed on the outmost surface. Electrochemical measurements and immersion tests revealed an improved degradable behavior for the Zn-implanted Fe samples. An approximately 12% reduction in the corrosion potential (Ecorr) and a 10-fold increase in the corrosion current density (icorr) were obtained after Zn ion implantation with a moderate incident ion dose, which was attributed to the enhanced pitting corrosion. The surface free energy of pure Fe was decreased by Zn ion implantation. The results of direct cell culture indicated that the short-term (4h) cytocompatibility of MC3T3-E1 cells was promoted by the implanted Zn on the surface.

Surface modification of TiO2 coatings by Zn ion implantation for improving antibacterial activities

TiO2 coating has been widely applied in orthopaedic and dental implants owing to its excellent mechanical and biological properties. However, one of the biggest complications of TiO2 coating is implant-associated infections. The aim of this work is to improve the antibacterial activity of plasma-sprayed TiO2 coatings by plasma immersion ion implantation (PIII) using zinc (Zn) ions. Results indicate that the as-sprayed TiO2 coating is mainly composed of rutile phase. Zn-PIII modification does not change the phase compositions and the surface morphologies of TiO2 coatings, while change their hydrophilicity. Zn-implanted TiO2 coatings can inhibit the growth of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), and the ability to inhibit S. aureus is greater than that to E. coli. Zn ion release and reactive oxygen species may be attributed to improving the antibacterial activity of TiO2 coating. Therefore, Zn-PIII TiO2 coatings on titanium suggest promising candidates for orthopaedic and dental implants.

Electronic structure and photoluminescence properties of Zn-ion implanted silica glass before and after thermal annealing

The results of XPS core-level and valence band measurements, photoluminescence spectra of a-SiO2 implanted by Zn-ions (E=30keV, D=1·1017cm−2) and Density Functional Theory calculations of electronic structure as well as formation energies of structural defects in silica glass induced by Zn-ion implantation are presented. Both theory and experiment show that it is energetically more favorable for implanted zinc ions to occupy the interstitial positions instead of cation substitution. As a result, the Zn-ions embedded to interstitials, form chemical bonds with the surrounding oxygen atoms, fabrication ZnO-like nanoparticles and oxygen-deficient SiOx matrix. The subsequent thermal annealing at 900°C (1h) strongly reduces the amount of ZnO nanoparticles and induces the formation of secondary α-Zn2SiO4 phase which markedly enhances the green emission.

Zinc ion implantation‑deposition technique improves the osteoblast biocompatibility of titanium surfaces.

The plasma immersion ion implantation and deposition (PIIID) technique was used to implant zinc (Zn) ions into smooth surfaces of pure titanium (Ti) disks for investigation of tooth implant surface modification. The aim of the present study was to evaluate the surface structure and chemical composition of a modified Ti surface following Zn ion implantation and deposition and to examine the effect of such modification on osteoblast biocompatibility. Using the PIIID technique, Zn ions were deposited onto the smooth surface of pure Ti disks. The physical structure and chemical composition of the modified surface layers were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. In vitro culture assays using the MG-63 bone cell line were performed to determine the effects of Zn-modified Ti surfaces following PIIID on cellular function. Acridine orange staining was used to detect cell attachment to the surfaces and cell cycle analysis was performed using flow cytometry. SEM revealed a rough ‘honeycomb’ structure on the Zn-modified Ti surfaces following PIIID processing and XPS data indicated that Zn and oxygen concentrations in the modified Ti surfaces increased with PIIID processing time. SEM also revealed significantly greater MG-63 cell growth on Zn-modified Ti surfaces than on pure Ti surfaces (P<0.05). Flow cytometric analysis revealed increasing percentages of MG-63 cells in S phase with increasing Zn implantation and deposition, suggesting that MG-63 apoptosis was inhibited and MG-63 proliferation was promoted on Zn-PIIID-Ti surfaces. The present results suggest that modification with Zn-PIIID may be used to improve the osteoblast biocompatibility of Ti implant surfaces.

Computer analysis of the AFM images of the nanopore system on the SiO2/Si structure surface, obtained by Zn ion implantation

A computer study of morphological characteristics using AFM images of a self-organized surface nanopore system in the structure of SiO2/Si(100) is performed. The nanopore system is obtained via Zn ion doping with subsequent thermal annealing. AFM images of the nanopore system are studied using the STIMAN 3D software. A correct quantitative estimate is made of the morphology of this nanopore system using a number of parameters (equivalent diameter, area, total area, and shape coefficient). Estimating the morphology of the self-organized surface nanopore system in the structure of SiO2/Si(100) allows us to narrow the possible practical applications of the resulting system in opto- and nanoelectronics.

Role of preparation and implantation-related defects for the magnetic properties of Zn0.9Co0.1O epitaxial films

A systematic variation of preparation conditions for epitaxial Zn0.9Co0.1O films grown by reactive magnetron sputtering on c-plane sapphire has been carried out to study the correlation of crystalline perfection with the corresponding magnetic properties. The crystalline perfection of the resulting films was found to vary over a wide range, nonetheless all samples were found to be paramagnetic. To further extend the study, three samples, which were paramagnetic in the as-grown state, were subsequently implanted using Cu, Li, and Zn ions. Only Zn ion-implantation was found to slightly alter the magnetic properties at low temperatures, while synchrotron-based techniques could not evidence the formation of a secondary, metallic Co phase. The origin of this weak, low-temperature magnetism is more likely to be carrier-mediated rather than defect-induced.

ZnO nanoparticle creating in a SiO2/Si structure using the Zn ion implantation with subsequent heat treatment

The distribution profiles of the dopant in the surface layer of a SiO2/Si structure implanted with Zn and O ions are studied via Rutherford backscattering spectroscopy for He2+ ions using the channeling technique. The redistribution of implanted impurities in the Si surface layer during the formation process of zinc oxide (ZnO) nanoparticles is analyzed. The effect of the annealing temperature on the formation process and growth of ZnO nanoparticles is studied. The sample-surface morphology is examined via atomic force microscopy. The optical absorption and photoluminescence of the implanted layers are studied.

Synthesis of nanoparticles in SiO2 by implantation of Cu and Zn ions and their thermal stability in oxygen atmoshphere

Cu nanoparticles (NPs) embedded in silica were synthesized by implantation of 45 keV Cu ions at a fluence of 1.01017 cm-2, and then subjected to post irradiation with 50 keV Zn ions at fluences of 0.51017 cm-2 and 1.01017 cm-2, respectively. Zn post ion implantation induced modifications in structures, optical absorption properties of Cu NPs as well as their thermal stability in oxygen ambient have been investigated in detail. Results clearly show that Cu-Zn alloy NPs could be formed in the Cu pre-implanted silica followed by Zn ion irradiation at a fluence of 0.51017 cm-2, which causes an unique surface plasmon resonance (SPR) absorption peak at about 516 nm. Subsequent annealing in oxygen atmosphere results in the decomposition of Cu-Zn alloy NPs, at 450 ℃, and thus, ZnO and Cu NPs appear in the substrate. Further increase of annealing temperature to 550 ℃ could transform all the Zn and Cu into ZnO and CuO. Moreover, results also demonstrate that introduction of Zn into SiO2 substrate could effectively suppress the oxidation of Cu NPs, meanwhile, the existence of Cu could promote thermal diffusion of Zn towards substrate surface, which enhances the oxidation of Zn. The underlying mechanism has been discussed.

Zn Ion Post-Implantation-Driven Synthesis of CuZn Alloy Nanoparticles in Cu-Preimplanted Silica and Their Thermal Evolution

Cu nanoparticles (NPs) were fabricated in silica by 45 keV Cu ion implantation at a fluence of 1.0 × 10(17) cm(-2) and were then subjected to implantation of 50 keV Zn ions at fluences of 1.0 × 10(16), 5.0 × 10(16), and 10.0 × 10(16) cm(-2), respectively. Our results clearly show that post Zn ion implantation could significantly modify structures and components of the preformed Cu NPs and thus the corresponding surface plasmon resonance (SPR) absorption can be modulated in a wide range. In particular, CuZn alloy NPs with unique SPR absorption were synthesized in Cu-implanted silica followed by Zn ion implantation at a fluence of 5.0 × 10(16) cm(-2). During subsequent annealing, two distinguished processes concerning CuZn alloy NPs (i.e., realloying and dealloying) were found that directly result from thermally driven diffusion of Zn atoms. Moreover, owing to Zn diffusion, lots of core-shell nanostructures consisting of Zn-related compound shells around Cu cores were observed after annealing at 500 °C and higher. The underlying mechanism concerning the formation and decomposition of CuZn alloy NPs is discussed and presented.