Ni Ion Implantation Research Articles

Optical and magnetic properties in well and barrier ZnS waveguides formed by MeV Ni and Cu ion implantation

Well and barrier waveguides were fabricated in zinc sulfide (ZnS) single crystals via nickel (Ni) and copper (Cu) ion implantation. Elastic collisions between the implanted ions and target nuclei were reconstructed using SRIM software. The prism coupling and end-face coupling methods were applied to capture the dark-mode spectrum and near-field intensity distributions, respectively, at 633 nm. The absorption spectra from the UV to visible band of the ZnS crystals before and after Ni and Cu ion implantation were collected on a spectrophotometer. Magnetic properties at room temperature were evaluated under a magnetic field of 3T.

Comparative study on effects of Ni ion implantation on amorphous carbon (a-C) coating and tetrahedral amorphous carbon (ta-C) coating

The effect of Ni ion implantation by 20 keV energy with fluences of 1 × 1016 cm−2 on tetrahedral amorphous carbon (ta-C) and amorphous carbon (a-C) films was studied. The ta-C and a-C films were deposited using filtered cathodic vacuum arc and high power impulse magnetron sputtering technique, respectively. The morphology, chemical bonding state, and mechanical and tribological performances of the coating before and after implantation were evaluated. The Raman results suggested that Ni implantation resulted in an increase in ID/IG ratio of ta-C film from 0.68 to 0.86, but led to a decrease of a-C films from 2.71 to 2.63. Ni ion implantation resulted in a decrease in wear resistance of ta-C films. The as-deposited and Ni-implanted a-C films both occur peeling off in the friction test, but Ni-implanted a-C films showed better wear resistance due to the increased elastic recovery rate and hardness in the modification layer.

Enhancement the graphitic nature of DLC by Au doping and incorporation of 300 keV Ni2+ ions in DLC thin films

This research work reflects the effects of 300 keV nickel (Ni) ions beam on the structural, morphological and electrical properties of DLC and Au doped DLC (Au-DLC) thin films. Pure and Au-DLC thin films have been deposited on glass substrate by RF magnetron sputtering. 300 keV Ni ions with exposure rate 2 × 104 and 4 × 104 atoms/cm2 have been implanted in Au-DLC thin films. XRD results show that Au formed cluster in DLC. When Ni ions are implanted in Au-DLC thin film at the exposure rate of 2 × 104 atoms/cm2 then both graphite and diamond like structures are appeared. When the exposure rate has increased upto 4 × 104 atoms/cm2 then film has only graphite nature. SEM shows the formation of agglomeration and clusters of Au and Ni in DLC due to its no bondage at ordinary conditions in DLC thin films. Four point probe shows average resistivity of films is decreased due to doping and implantation of Au and Ni ions, respectively. This work provides a cost effective study of DLC thin film as a conducting layer in many optoelectronic applications such as a counter electrode in dye-sensitized solar cells.

Structure and Transport Properties of Nickel-Implanted CoSb3 Skutterudite Thin Films Synthesized via Pulsed Laser Deposition

The present study reports the effect of Ni ion implantation on the structural, compositional, electrical, and thermoelectric properties and electronic structures of CoSb3 skutterudite thin films deposited on Si substrate by pulsed laser deposition. Ni ions were implanted at 200 keV in CoSb3 thin films at three different fluences: 3 × 1015, 6 × 1015, and 1.5 × 1016 ions/cm2. X-ray diffraction of Ni-implanted films shows an additional phase of Co0.75Ni0.25Sb3. The electrical measurement of pristine films exhibits typical semiconductor behavior, while the Ni-implanted films show an abrupt increase in resistivity, which may be attributed to the formation of Co0.75Ni0.25Sb3 and material modification by the energetic ion beam. The Seebeck coefficient measurements imply that all the films are n-type with maximum Seebeck coefficient of ∼75 μV/K at ∼410 K for 2% Ni-implanted film which is about 7 times higher than the pristine CoSb3 film. The X-ray absorption study of Ni, Co, and Sb spectrum confirms that Ni ions ...

Ni-doped amorphous iron phosphide nanoparticles on TiN nanowire arrays: An advanced alkaline hydrogen evolution electrocatalyst

Efficient and low-cost non-precious-metal-based electrocatalysts are crucial to the commercial success of the hydrogen evolution reaction (HER) under alkaline conditions. Herein, a step-by-step strategy to prepare a hierarchical structure assembled from Ni-doped amorphous FeP nanoparticles, porous TiN nanowires, and graphitic carbon fibers (Ni-FeP/TiN/CC) is described. The FeP/TiN/CC composite is plasma-implanted with Ni ions to modify the electronic structure and produce an amorphous surface. Simultaneous doping and amorphization of FeP by Ni ion implantation to enhance the HER activity is achieved for the first time. The flexible and freestanding Ni-FeP/TiN/CC catalyst produced on a carbon cloth can serve directly as an electrode in HER in an alkaline medium. The Ni-FeP/TiN/CC catalyst delivers excellent HER performance including an overpotential of 75 mV to generate a cathodic current density of 10 mA cm−2, a Tafel slope close to that of commercial Pt/C catalysts, and long lifetime indicated by a more constant cathodic current density during continuous operation for 10 h. The remarkable HER activity is attributed to the combined effects rendered by the Ni and Fe atoms in the Ni-doped FeP nanoparticles, active amorphous surface, as well as conductive nanowire scaffold, which expose a large amount of active sites, enhance the charge transfer efficiency, and prevent the catalysts from migration and aggregation.

The effect of fluence on the magnetic properties of superparamagnetic iron-nickel nanoparticles in SiO2 made by dual Ni and Fe low energy ion implantation

Superparamagnetic Ni1−yFey nanoparticles were made in a SiO2 film by 10keV ion beam implantation of Ni followed by Fe with a Ni fluence of 4×1016at.cm−2 and a Fe fluence fraction of 0.47. Nearly all of the moments magnetically ordered, which was not reported for an implanted film made with a Fe fluence fraction of 0.56 and half the Ni fluence. The temperature dependence of the saturation moment is remarkably similar for low and high Ni fluences where there is also the presence of very thin spin-disordered shells. The higher Ni fluence leads to a significant enhancement of the susceptibility by a factor of 9 when compared with the lower fluence sample. This enhancement is likely to be due to a larger magnetically ordered volume fraction.

Compositional, structural, and optical changes of polyimide implanted by 1.0 MeV Ni+ ions

The ion irradiation leads to deep structural and compositional changes in the irradiated polymers. Ni+ ions implanted polymers were investigated from the structural and compositional changes point of view and their optical properties were investigated. Polyimide (PI) foils were implanted with 1.0MeV Ni+ ions at room temperature with fluencies of 1.0×1013–1.0×1015cm−2 and two different ion implantation currents densities (3.5 and 7.2nA/cm2). Rutherford Back-Scattering (RBS) and Elastic Recoil Detection Analysis (ERDA) were used for determination of oxygen and hydrogen escape in implanted PI. Atomic Force Microscopy (AFM) was used to follow surface roughness modification after the ion implantation and UV–Vis spectroscopy was employed to check the optical properties of the implanted PI. The implanted PI structural changes were analysed using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR).High energy Ni-ion implantation causes only a minor release of hydrogen and oxygen close to the polymer sub-surface region in about 60nm thick layer penetrated by the ion beam; especially at ion fluencies below 1.0×1014cm−2. The mostly pronounced structural changes of the Ni implanted PI were found for the samples implanted above ion fluence 1.0×1015cm−2 and at the ion current density 7.2nA/cm2, where the optical band gap significantly decreases and the reduction of more complex structural unit of PI monomer was observed.

Transition metal swift heavy ion implantation on 4H-SiC

This work reports on the realization of Quantum Ring (QR) and Quantum Dot (QD) like structures on 4H-SiC through SHI implantation and on their Raman studies. 4H-SiC is SHI implanted with Transition Metal (TM) Ni ion at different fluences. It is observed that a vibrational mode emerges as the result of Ni ion implantation. The E2 (TO) and the A1 (LO) are suppressed as the fluence increases. In this paper Raman and AFM studies have been performed at room temperature and the queer anomalies are addressed so new devices can be fabricated.

The effect of Ni pre-implantation on surface morphology and optical absorption properties of Ag nanoparticles embedded in SiO2

The effect of Ni ion fluence on Ag nucleation and particle growth was investigated by sequentially implantation of 60keV Ni ions at fluences of 1×1016, 5×1016, 1×1017 ions/cm2 and 70keV Ag ions at a fluence of 5×1016 ions/cm2. Due to the modification of the deposition and accumulation process of Ag implants caused by Ni pre-implantation, the surface morphology, structures, and optical absorption properties of the Ag nanoparticles (NPs) depends strongly on the Ni fluences. UV–vis absorption spectroscopy study showed that the introducing of Ni atoms lead to intensity decrease in the Ag SPR band. Remarkable local concentration increase of Ag profiles appeared for the sample pre-implanted by Ni ions of 5.0×1016 ions/cm2. In particular, the AgNi alloy NPs with dual absorption peaks centered at 406nm and 563nm have been formed after 600°C annealing in Ar atmosphere. However, at a low fluence of 1.0×1016 ions/cm2, only small increase of the local Ag concentration than the Ag ions singly implanted sample can be observed. At a high fluence of 1.0×1017 ions/cm2, lots Ag atoms are trapped close to the surface, which result in heavy sputtering loss of Ag atoms and the sublimation of Ag atoms after 600°C annealing.

Local structure study of the Ni nanoparticles embedded in SiO2 by ion implantation

The extended x-ray absorption fine structure (EXAFS) and the Atomic force microscopy (AFM) have been used to study the local structural information of Ni nanoparticles implanted into glass. Three different concentrations of nickel nanoparticle samples were fabricated by metal vapor vacuum arc (MEVVA) source on amorphous silicon dioxide substrate at room temperature. With the increase of Ni ion implantation, the interatomic distance and the nearest neighbor coordination number of the nearest Ni–Ni bond and Ni–O bond of nickel nanoparticle presents certain regular change.

AgNi alloy nanoparticles embedded SiO2 films: Synthesis and structure

AgNi alloy nanoparticles (NPs) embedded in SiO2 were prepared by sequentially implantation of 60keV Ni ions and 70keV Ag ions at the same fluence of 5.0×1016cm−2 and post-thermal annealing at 600°C in Ar atmosphere. UV–vis absorption spectroscopy study showed that the introducing of Ni atoms lead to dual absorption peaks centered at 406nm and 563nm. The incorporation of Ni elements in Ag NPs damped SPR absorption intensity. X-ray photoelectron spectroscopy and Grazing X-ray diffraction results were consistent with the presence of metallic Ag surrounded by Ni or NiO. Cross-sectional transmission electron microscopy observations further confirmed the fabrication of AgNi alloy NPs with high volume fraction.

Supercontinuum and THz generation from Ni implanted LiNbO3 under 800 nm laser excitation

In this letter, the authors present first observation of supercontinuum and terahertz generation from Ni implantation of LiNbO3 crystal substrate. LiNbO3 single crystal is grown by Czochralski method. Metal nanoparticles synthesized by Ni ion implantation were implanted into LiNbO3 single crystal using metal vapor vacuum arc (MEVVA) ion source. 1kHz, 35fs laser pulsed centered at 800nm were focused onto the samples. The supercontinuum spectra of the sample are obtained. Terahertz was generated via optical retification. The findings suggest that under the investigated implantation parameter, a spectral component in excess of 0.5THz emission were found from Ni ion implantation of LiNbO3.

Microstructure and friction performance of copper film fabricated by ion implantation assisted electroless plating on PTFE

The polytetrafluoroethylene (PTFE), which was implanted with Ni ion to different energy and doses, fabricated metallic structures by selective electroless copper plating. The characteristic and microstructure of the copper film were studied using SEM and X-ray diffraction. Friction performance of the interface between copper film and basal body of PTFE was tested with a CETR UMT-2 (CETR Co., Campbell, CA, USA) multifunction micromechanics instrument. The test loads were 10, 20 and 40 N, while the line velocity was 8 mm s−1, and the frequency of data acquisition was 1 Hz. The Ni ion implantation replaces the complicated electroless plating surface pretreatment, and it is an assisted technique of electroless plating of copper on the surface of PTFE and plate Cu directly on its surface. Continuous, prepressing and uniformity plating was obtained with proper technique parameters and the dosage of Ni+. The frictional performance comprehensive property of copper film was remarkably influenced by different plating methods, annealing treatment and testing loads under unlubricated condition. The friction coefficients and wear rates changed with the varied load. Annealing treatment improves the tightness and uniformity of the copper film, while it decreases its cavity. Friction performance of copper film was thus increased. The mechanisms of friction and wear of copper film under different test conditions are also discussed.

Effects of ion implantation on the brazing properties of high purity alumina

In this study, ion implantation was used as a surface modification method for active and inactive brazing of alumina ceramics to metals. Alumina was implanted with Ti ions at acceleration voltages of 35 kV and 55 kV at doses ranging between 2 × 10 17 and 1 × 10 18 ions/cm 2, with Ni ions at an acceleration voltage of 55 kV at doses ranging between 2 × 10 16 and 6 × 10 17 ions/cm 2, and with Al ions at 55 kV with a dose of 2 × 10 17 ions/cm 2. After implantation, the brazing of alumina to Nb was performed using the active brazing metal Ag 70Cu 27Ti 3 (wt.%) at 850 °C/870 °C and the inactive brazing metal Ag 72Cu 28 (wt.%) at 830 °C in a vacuum respectively. The surface properties of implanted alumina, e.g., implanted ions depth and concentration distribution, newly formed phases, sheet resistance etc., were studied by Rutherford backscattering (RBS), Glancing X-ray diffraction (GXRD) and four-probe method. Shear strengths of the active and inactive brazing joints were measured. Microstructures of the joints were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). There is no obvious evidence that Ti and Ni ion implantation can enhance the quality of active brazing joints. However, it has been found that Al ion implantation can significantly increase the shear strengths of active brazing joints to average value 139 MPa, which is 30% greater than in non-ion implantation (107 MPa). It has also been found that ion implantation can improve the shear strengths of alumina–Nb inactive brazing joints. Maximum average shear strength of the inactive brazing joints can reach 43 MPa when Ni ions were used at an acceleration voltage of 55 kV in a dose of 2 × 10 17 ions/cm 2. Finally, the effects of ion implantation on alumina–Nb active and inactive brazing were discussed.

Nickel‐related defects in ZnO – A deep‐level transient spectroscopy and photo‐capacitance study

AbstractElectronic defects in nickel‐doped zinc oxide thin films have been investigated by means of capacitance spectroscopy. The samples were grown by pulsed laser deposition on a‐plane sapphire substrates. Nickel was introduced into the films (a) during growth and (b) by implantation of Ni ions and subsequent thermal annealing. From deep‐level transient spectroscopy it was concluded that a nickel‐related trap, TNi2, with an energy level approximately 540 meV below the conduction band edge was formed. Photo‐capacitance (PCAP) measurements performed on the nickel‐implanted sample proved the existence of a further nickel‐related trap, TNi1, in the midgap. The photo‐ionisation cross‐section spectra of this state were calculated from the PCAP transients and gave evidence that TNi1 and TNi2 are two levels of the same defect, TNi, which is possibly nickel on a tetrahedral lattice site. A model for TNi is proposed.

Influence of implantation induced Ni-doping on structural, optical, and morphological properties of nanocrystalline CdS thin films

Ni-doped CdS thin films were prepared by 90 keV Ni+ implantation at room temperature. Ni-ion implantation induced modifications in structural, optical, and morphological properties are studied for a wide range of impurity concentrations (1.86–10.19 at.%). Addition of Ni+ ions does not lead to any structural phase transformation or formation of metallic clusters or secondary phase precipitates. However, it induces structural disorder leading to a reduction in the optical band gap from 2.39 to 2.28 eV following Ni implantation up to 3 × 1016 ions cm−2. This is addressed on the basis of band tailing due to the creation of localized energy states and implantation induced grain growth. Moreover, Ni-doping is found to modify the luminescence properties by creating shallow acceptor states.

Low Specific Contact Resistance of NiSi and PtSi to Si: Impact of Interface

We recently reported low specific contact resistance values of NiSi and PtSi to silicon. In recent publications, such low values were attributed to dopant segregation. In this work, we tested this hypothesis by spreading resistance probe and secondary ion mass spectroscopy analyses. The observed weak dopant segregation could not explain lowering the contact resistance by orders of magnitude. Interface damage, intentionally created using Ni ion implantation, led to an increase of contact resistance (1–2 orders). We conclude that the low contact resistance is intrinsic to a high-quality silicide-silicon interface and can be obtained without active dopant segregation.

The electrochemical behavior of anodic alumina films implanted with Ni ions

The motivation of this study is to investigate the possibility of improving corrosion resistance of anodic films on aluminum by Ni ions implantation. The implantation of Ni ions was carried out using a MEVVA source at an energy of 40 keV and a dose of 5.0 × 10 17 ions cm −2. Electrochemical impedance spectroscopy (EIS) was used to study the influence of the ions implantation on electrochemical behavior of anodic films in basic NaCl solution. The results show that Ni ions implantation strengthens the self-sealing process of the anodic film in solutions. The resistance of the porous layer ( R p) increases and the capacitance of the porous layer ( C p) decreases after implantation of Ni ions. For the anodic layer without implantation of Ni ions, as the immersion time increases, changes of C p and R p are slower. A more rapid change is observed for the anodic films implanted with Ni ions. XPS results reveal that Ni is present on the anodic film surface as metallic Ni and nickel oxide (NiO). AFM results show that the implantation of Ni ions made the surface structure and morphology of anodic films more uniform and less rough. The semi conductive property of anodic films in basic NaCl solution with and without Ni ions implantation was studied by Mott–Schottky analysis. For anodic films implanted with Ni ions, the profile is characteristic of p-type semiconductors from −1.0 V to −0.5 V. By expanding the M–S plots at high potentials to more positive potential than −0.5 V, the anodic film shows n-type characteristic. Possible reasons for the observed changes in surface properties are discussed.

Microstructural modifications of Ni–Ti shape memory alloy thin films induced by electronic stopping of high-energy heavy ions

The current study is part of an overarching goal to develop an ion implantation process for producing cyclic actuating elements used in microelectromechanical systems. The damage produced by high-energy ions can be used as a means to selectively suppress the martensitic transformation and bias the motion of shape memory alloy thin films Ni–Ti. In order to optimize the performance of these devices, detailed knowledge of the influence of ion implantation on the microstructure is needed. Recent experiments have shown that complex microstructures are formed after 5 MeV Ni ion implantation. In particular, the extensive surface amorphization and the depth distributions of the irradiation induced phase transformations, which were more prominent at shallower depths than expected, did not correlate with ion transport theories involving nuclear stopping damage distributions. Although electronic stopping effects are normally neglected in metals in these energy regimes, they may explain the unexpected surface amorphization since electronic stopping is the prevalent mode of ion energy transfer at shallow depths. Therefore, swift ion irradiation experiments were conducted to assess the effects of electronic stopping on the damage production. Microstructural observations showed that significant damage was produced from ions possessing low electronic stopping powers (<9 keV/nm) near those of 5 MeV Ni ions (3 keV/nm), confirming, in part, that electronic stopping effects contribute to the damage processes.

Control of saturation magnetization, anisotropy, and damping due to Ni implantation in thin Ni81Fe19 layers

The layer magnetization, the saturation magnetization as well as the magnetic anisotropy, and damping behavior of 20nm thick Ni81Fe19 films have been modified by 30keV Ni ion implantation with fluences up to 1×1016Ni∕cm2 (≈5at.%). With increasing ion fluence a magnetic dead layer of increasing thickness is formed which leads to a reduction of the total magnetization. In addition, the saturation magnetization of the residual ferromagnetic film decreases due to, both, a shift in stoichiometry and radiation damage. Accordingly a reduction of the magnetic anisotropy and a strong enhancement of the magnetic damping parameter are observed. Moreover, ion implantation in an applied magnetic field allows the setting of the uniaxial anisotropy direction irrespective of its original orientation. Static and dynamic magnetic properties of Ni81Fe19 films can be tailored over a wide range after film deposition.