RF Mode Research Articles

DAC phase and amplitude noise experimental studies in RZ, NRZ and RF modes

Amplitude and duration of pulses generated by current cells of multimode DAC may differ in real DACs. In this case the problem arises of current pulse parameters defining, their relationship with frequency domain response and noise parameters of DAC, which can be experimentally determined. The article describes the measurements of frequency domain response, phase noise and amplitude noise of multimode DAC output signal in RZ, NRZ and RF (mixed) mode. Phase noise and amplitude noise of multimode DAC in RZ and RF modes calculation uses experimental data obtained in RZ mode. Measurement and consequent calculation of AD9739 DAC phase and amplitude noise confirmed the theoretical analysis.

Suppression of multipacting growth in a superconducting spoke resonator by the use of higher order modes

Abstract Multipacting is a vacuum discharge phenomenon that constrains the performance of accelerator structures and various microwave devices significantly. The different ways to mitigate multipacting discharge have been a central research goal in Accelerator Physics & Technologies for a prolonged period. In this work, both Monte-Carlo and particle-in-cell (PIC) simulations show that the multipactor avalanche can be mitigated, by the use of Higher Order Modes (HOMs). The intuition behind the approach of using HOMs to suppress multipacting has been explained first. Then, the multipacting suppression has been demonstrated in a simple 1-D metallic gap, when it is exposed to a second carrier frequency in addition to fundamental rf mode, with the help of a Monte-Carlo simulation code. Finally, a detailed PIC simulation has been carried out using CST Microwave studio, to investigate the effect of various HOMs on the multipactor growth in a superconducting spoke cavity. It is observed that a slight excitation of some particular modes can drastically diminish the multipactor growth. Simulation has been done first without any HOMs, to calculate the growth rate and also to spot the discharge location. Next, among various HOMs (more specifically, quadrupole modes), only those have been selected, whose magnetic field locations coincide with the multipacting prone zone of the cavity. In a simulation study, the presence of these preselected quadrupole modes has been found to exhibit a substantial suppression effect on the multipacting growth of the cavity.

Analyzing the phase and amplitude noise of RZ, NRZ and RF DACs

This article considers a multi-mode RF DACs phase and amplitude noise for non-return-to-zero (NRZ), return-to-zero (RZ), and mix/RF reconstruction waveforms under the assumption that two switch pairs (or two channels) in each current switch cells are alternately active in every clock cycle, Analysis shows that each channel of multimode DAC is completely characterized with RZ mode, and all other modes can be derived from this mode, in particular NRZ mode is not a complete analog of conventional DAC performance when reconstruction pulse duration and period are equal. When determining phase and amplitude noise of multi-mode RF DAC, one should keep in mind the phase shift between two switch pairs output pulses spectral components in NRZ and RF modes. This phase shift depends upon DAC mode (NRZ or RF) and output oscillation frequency. As consequence an analysis indicates that the 3 dB improvement of 1/F phase noise can be achieved in 1st Nyquist zone when using NRZ mode, the same in 2nd Nyquist zone with RF mode if amplitude noise of DAC switch pairs is negligible. The independence of 1/F noise from clock frequency has simple physical interpretation. As correlation period of 1/F noise is significantly greater than output oscillation period, the delay of this oscillation caused by phase fluctuations in DAC is the same for any mode, and analysis of noise spectral density for conventional DAC can be extended to multi-mode RF DACs.

Relationship between imaging parameters and distortion in magnetic resonance images for gamma knife treatment planning.

In magnetic resonance imaging (MRI), it is necessary to reduce image distortion as much as possible because it suppresses the increase in the planning target volume. This study investigated the relationship between imaging parameters and image distortion when using G-frames. The images were obtained using a 1.5-T MRI system with a 09-101 Pro-MRI phantom. Image distortion was measured by changing the RF pulse mode, gradient mode, asymmetric echo, and bandwidth (BW). The image distortion was increased in the high RF mode than in the Normal mode. The image distortion increased in the following order: Whisper≦Normal<Fast in the different gradient modes. The image distortion increased in the following order: Without≦Weak<Strong in the different asymmetric echo modes. The image distortion increased in the following order: 300Hz/pixel>670Hz/pixel≧REF (150Hz/pixel) in the different Bw. The relationship between parameters and image distortion was clarified in this study when G-frames were used for gamma knife therapy. There is had relationship between the parameters causing variation in the gradient magnetic field and image distortion. Therefore, these parameters should be adjusted to minimize distortion.

(Invited) Gallium Oxides Devices for Grid-Scale Power Electronics and High Power Switched Mode RF Amplifiers

Within a decade of the first demonstration of a MESFET device, monoclinic β-Ga2O3 (Ga2O3) devices have made incredible progress in breakdown voltages, power device figure of merit and high-speed performance. It has emerged as a promising ultra-widebandgap semiconductor for next generation power, GHz switching and RF applications. In this talk, we will present an overview of our studies on fundamental transport properties, kilovolt class power MOSFETs and aggressively scaled RF devices. The large bandgap of Ga2O3 leads to a high critical field strength. This high field strength in combination with demonstrated room temperature mobility and calculated electron velocity leads to a higher Baliga’s Figure of Merit (BFoM) and Johnston Figure of Merit (JFoM) than current commercially available widebandgap technologies. Additionally, the large bandgap also enables high temperature operation and radiation hardness making it attractive for space applications such as Mars and Venus missions.In the first part, we will discuss the deep insights gained from the first-principles based transport calculations in Ga2O3. We will discuss the limits to low field mobility, saturation velocities and impact ionization coefficients. The impact of the plasmon-phonon coupling on the phonon limited transport will be discussed. We will present the experimental signatures of plasmon-phonon coupling and anti-screening behavior in ionic gated accumulation layers.Next, I will describe our work on the lateral MOSFETs with improved field plate design and beyond-kV breakdown. Temperature dependent analysis and device simulation suggest an extrinsic breakdown mechanism outside the channel. A simple and yet effective SU-8 polymer passivation technology was developed that results in significant improvement in breakdown voltages. The higher field strength of the SU-8 polymer enables a significant increase in breakdown voltage to 8 kVs in lateral MOSFETs. However, these devices show a high Ron, which is due to the depletion caused by RIE of the channel. We will present the use of ultra-high vacuum annealing techniques to improve the on-resistance of the devices still maintaining the multi-kilo-volt rating of the devices.Due to its high JFoM, Ga2O3 is a potential candidate for high power density RF amplifiers. We will also present the performance advancement that can be obtained in RF power performance using Ga2O3 technology. We will present the challenges in the technology and potential solutions. We will present the experimental DC and pulsed measurements on laterally scaled MOSFETs with 100 nm gate length. Severe DC-RF dispersion was observed which is attributed to the RIE damage and surface states on the oxide. Passivation of the devices shows reduced current collapse. Using aggressive gate lengths and gate-source spacing scaling, (AlxGa1-x)2O3/Ga2O3 heterostructure FETs were fabricated that show record high RF performance. The device transconductance was limited by the regrowth interface resistance. Ex-situ silicon nitride passivation was shown to be effective to reduce DC-RF dispersion. Recently, thin channel MOSFETs with deep-sub-micron gate lengths and source/drain regrowth have demonstrated devices with simultaneously low on resistance, high frequency, high voltages.

Optical monitoring of DC/RF plasma sputtering for copper oxide film growth at low temperature

DC/RF plasma sputtering process for the growth of copper oxide thin film was studied by optical emission spectroscopy. The films were produced by a balanced magnetron sputtering system nearly at room temperature. The influence of applied power in DC and RF mode and Ar/O2 flow ratio on the film properties was investigated as well as their relationship to the plasma species and the main chemical reactions during the film growth. It was found that the concentration of active species in the plasma and their abundance ratio is very effective in the reactions related to the film growth process and the properties of the deposited film. It was shown that copper oxide film with CuO phase owing low energy band gap can be synthesized at low temperatures by controlling the ionization rate, the energy of the active species, the film growth rate, and finally the relative concentration of copper to oxygen species in the plasma. CuO thin films (Eg=1.28 eV) were achieved in DC mode at the lowest applied power (50 W) and in the lowest Ar/O2 flow ratio (2/1). This oxide phase was also observed for two both the synthesized films in RF mode, at 50 W (Eg=1.39 eV) and 100 W (Eg=1.23 eV) in an Ar/O2 flow ratio of 2/1.

Microstructural characterization and thermal stability of He charged amorphous silicon films prepared by magnetron sputtering in helium

Sputtering of silicon in a Helium magnetron discharge has been reported as a bottom-up procedure to obtain amorphous Si films containing high amounts of gas-filled nanopores. Here we compare the microstructure and composition of Si–He nanocomposite films deposited by magnetron sputtering (MS) with 4He in DC or RF and 3He in RF operation modes. Electron microscopy (SEM and TEM), X-ray diffraction (XRD) and ion beam analysis (IBA) have been used to analyze the films and to investigate the in-situ and ex-situ thermal evolution. Depending on deposition conditions different in depth compositions, nanopore size and shape distributions, porosity and He content could be obtained. The presence of impurities (i.e. oxygen) has shown to promote He diffusivity reducing He accumulation. The start temperature of He-release varied in the range 473–723 K without films crystallization. Films grown in RF mode reached contents of 32 and 29 at% of 4He and 3He and were respectively stable up to 573 and 723 K both in vacuum and under inert gas flow. In-situ p-EBS (proton Elastic Back Scattering) allowed monitoring the He release accompanied by blistering/delamination effects visualized by SEM. These results show the potentiality of annealing to hold nano-porous structures after liberation of trapped gas.

A new design for the RF electron gun of the Iranian Light Source Facility (ILSF)

A new π mode RF electron gun is proposed for the Iranian Light Source Facility. This RF gun will be fabricated using a newly developed method based on clamping the parts together instead of vacuum brazing. In this method, RF contact and vacuum seal are mutually provided by a special copper gasket. The first section of this article describes the new π mode RF gun and its expected performance in detail. The report of our recent R&D tests on the new fabrication method is discussed in the next section. We performed the RF and vacuum measurements on a single-cell structure, and the copper gasket provided suitable RF contact, and a vacuum pressure of 2.5×10−7 mbar was also reached after 1 h of pumping with a turbo-molecular pump without baking. In the last section, we investigated using a high-current and low-emittance DC triode electron gun to be mounted on the RF gun as an alternative cathode assembly. The simulation results of this proposed scheme were compatible with our previous studies. The research and development of the new π mode RF electron gun and the proposed cathode assembly will begin soon.

CBM Gas Content Prediction Model Based on the Ensemble Tree Algorithm with Bayesian Hyper-Parameter Optimization Method: A Case Study of Zhengzhuang Block, Southern Qinshui Basin, North China

Gas content is an important parameter for evaluating coalbed methane reservoirs, so it is an important prerequisite for coalbed methane resource evaluation and favorable area optimization to predict the gas content accurately. To improve the accuracy of CBM gas content prediction, the Bayesian hyper-parameter optimization method (BO) is introduced into the random forest algorithm (RF) and gradient boosting decision tree algorithm (GBDT) to establish CBM gas content prediction models using well-logging data in the Zhengzhuang block, south of Qinshui Basin, China. As a result, the GBDT model based on the BO method (BO-GBDT model) and the RF model based on the BO method (BO-RF model) were proposed. The results show that the mean-square-error (MSE) of the BO-RF model and the BO-GBDT model can be reduced by 8.83% and 37.94% on average less than that of the RF and GBDT modes, indicating that the accuracy of the models optimized by the BO method is improved. The prediction effect of the BO-GBDT model is better than that of the BO-RF model, especially in low gas content wells, and the R-squared (RSQ) of the BO-GBDT model and the BO-RF model is 0.82 and 0.66. The accuracy order of different models was BO-GBDT &gt; GBDT &gt; BO-RF &gt; RF. Compared with other models, the gas content curve predicted by the BO-GBDT model has the best fitness with the measured gas content. The rule of gas distribution predicted by all four models is consistent with the measured gas content distribution.

Multifactorial investigations of the deposition process – Material property relationships of ZnO:Al thin films deposited by magnetron sputtering in pulsed DC, DC and RF modes using different targets for low resistance highly transparent films on unheated substrates

We present a comprehensive study of the many parameters available in magnetron sputtering (including sputtering modes and target choice) to obtain low-resistivity ZnO:Al (AZO) films. The material is widely studied by many groups, however most of the reports focus on the optimization of one parameter, making the translation to another system cumbersome. We aimed to provide a general blueprint for a quick optimization of the process parameters for low resistivity, high crystalline quality AZO films. We found that it was the total argon pressure that controlled the outcomes most and that it is very important to have it the lowest possible. We show that the deposition power and other parameters do not influence the films in such a way. We tested two different (black and white) AZO targets and also did not found many differences, which may also be relevant for the researchers starting their work and wondering if the target they ordered would work well. We obtained very low film resistivities, at 1.2 mΩcm while depositing at room temperature, which is comparable with state-of-the-art results for deposition on heated substrates. We argue, that the sputtering configuration with a short target to substrate distance is responsible for this, opening up the way for low resistivity AZO deposition on heat-sensitive substrates.

Frequency-Reconfigurable SP4T Switch With Plaid Metal Transistors and Forward Body Biasing for Enhanced RON × COFF Characteristics

A frequency-reconfigurable SP4T switch is presented, in which <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\text {ON}} \times {C}_{\text {OFF}}$ </tex-math></inline-formula> characteristics of switch transistors are enhanced with plaid metal transistors and forward body biasing. Plaid metal transistors (PMT) with forward body bias (FBB) are used for all of the transistors to enhance the FoM. The plaid patterned metal accesses of a transistor for the source and drain decrease the extrinsic resistance and capacitance. FBB increases the overdrive voltage of a transistor and decreases the on-resistance. The SP4T switch includes main switch matrices that route an input signal to four-outputs, a switched inductor (SI) network, and a mode-selection switch. The SI network connected through the mode-selection switch resonates out the off-capacitances of the main switch matrices at RF in the RF mode. The SP4T switch operates without the SI network in DC mode. The SP4T switch is implemented in a 28-nm FDSOI CMOS process. The core area occupies 0.2 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The switch shows less than 2 dB insertion loss from DC to 4.4 GHz in the DC mode and from 4.4 to 5.3 GHz in the RF mode, where isolations are more than 16.8 dB and 18 dB, respectively.

ИМИТАЦИОННАЯ МОДЕЛЬ ДЛЯ ИССЛЕДОВАНИЯ РАБОТЫ КЛЮЧЕВЫХ ВЧ УСИЛИТЕЛЕЙ МОЩНОСТИ С РАЗДЕЛЬНЫМ УСИЛЕНИЕМ СОСТАВЛЯЮЩИХ НА УЗКОПОЛОСНУЮ НАГРУЗКУ

Introduction: High-efficiency switching mode envelope elimination and restoration (EER) RF power amplifiers (PA) are the most promising of a number of "synthetic" power amplification methods for a wide variety of applications. However, when they operate on a mismatched narrow-band load, for example, an electrically short antenna, additional out-of-band emission occurs, which limits the EER PA scope. The purpose of the work is to develop a simulation model for studying the EER switching mode RF PA operation for a narrow-band load. The choice of transient analysis method and use of the freely distributed simulation environment Micro-Cup 12 are substantiated. A number of original solutions are proposed to reduce the computation time. The description of developed model is given, which makes it possible to study the features of the EER PA operation on a narrow-band antenna on a real signal with amplitude&amp; phase modulation fragment. As an example, a DRM digital radio OFDM signal with 10 kHz bandwidth is used. Studies conducted using this model can be proportionally scaled for any frequency band and will allow further development of technical requirements for the EER PA blocks characteristics. Some calculations results showing the developed model adequacy are presented. Practical significance: the use of this model for the subsequent search for solutions to ensure the possibility of EER PA operation for a narrower band load will expand the scope of these high-efficiency power amplifiers.

Novel open cavity design for rotating mode rf pulse compressors

A new $X$-band high-power rotating mode SLAC energy doubler (SLED)-type rf pulse compressor is proposed. It is based on a novel cavity type, a single open bowl-shaped energy storage cavity with high-quality factor and compact size, which is coupled to the waveguide using a compact rotating mode launcher. The novel cavity type is applied to the rf pulse compression system of the main linac rf module of the klystron-based option of the Compact Linear Collider. Quasispherical rotating modes of ${\mathrm{TE}}_{1,2,4}$ and ${\mathrm{TE}}_{1,2,13}$ are proposed for the correction cavity and storage cavity of the rf pulse compression system, respectively. The storage cavity working at ${\mathrm{TE}}_{1,2,13}$ has a quality factor above 240 000 and a diameter less than 33 cm. The design of the pulse compressor and in particular of the high-Q cavity will be presented in detail.

Theoretical foundations for the evanescent mode oscillator (EMO) as a high-efficiency source of millimeter-wave and terahertz radiations

Evanescent mode oscillators (EMO) are investigated as high-efficiency sources of millimeter-waves and low-frequency parts of terahertz radiation. EMO can be considered a high-efficiency version of the extended interaction oscillator (EIO) using the evanescent resonance mode (ERM) of a slow-wave structure. It has been shown quantitatively that the efficiency of the EMO is superior to that of the conventional EIO having the same periodic unit cell. The condition to have an evanescent resonant mode in a chain is derived in this article. EMO threshold excitation condition is expressed in terms of the beam and RF mode parameters. A Typical EMO is systematically modeled, and its performance is checked with a particle-in-cell simulation software package. The excitation of the ERM modes is illustrated, with the results being close to the prediction of the non-linear model used in the paper.

Experimental proof test of CW mode RF modulated grid-controlled thermionic electron gun

A CW mode RF modulated grid-controlled thermionic electron gun was proposed by Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS) for some high average current electron accelerators requirements. The RF modulated grid-controlled thermionic electron gun was selected for these purposes due to its simplicity and cost savings. The experimental proof test of this type electron gun was conducted. The RF power supply at 107.5 MHz for the grid modulation can be adjusted from 10 W to 70 W. The RF power is coupled into the gun of grid-cathode through a RF&DC modulator. The electromagnetic field and RF simulation of the modulator is presented here. The gun structure and the beam dynamics design are also shown in the paper. The cathode assembly and the electron guns are tested on a 10 kV test bench for beam characterization. The CW mode 107.5 MHz electron beam obtained from the proof test, which is important for future high average current electron injectors development.

InAs/InP Quantum Dash Semiconductor Coherent Comb Lasers and their Applications in Optical Networks

We report on the design, growth, and fabrication of InAs/InP quantum dash (QD) gain materials and their use in lasers for optical network applications. A noise performance comparison between QD and quantum well (QW) Fabry–Perot (F-P) lasers has been made. By using the QD gain material we have successfully developed and assembled C-band coherent comb laser (CCL) modules with an electrical fast feedback loop control system to ensure a targeted mode frequency spacing. The frequency spacing was maintained within ±100 ppm and the operation wavelengths locked on the desired ITU grid within 0.01 nm over a period of several months. We also investigated a 25-GHz C-band QD CCL with an external cavity self-injection feedback locking (SIFL) system to reduce the optical linewidth of each individual channel to below 200 kHz in the wavelength range from 1537.55 nm to 1545.14 nm. The RF mode beating signal 3-dB bandwidth was also reduced from 9 kHz to approximately 500 Hz with this SIFL system. These QD CCLs with ultra-low relative intensity noise (RIN), ultra-narrow optical linewidth, and ultra-low timing jitter are excellent laser sources for multi-terabit optical networks. Using a 34.2 GHz QD CCL we demonstrate 10.8 Tbit/s (16QAM 48 × 28 GBaud PDM) coherent data transmission over 100 km of standard single mode fiber (SSMF) and 5.4 Tbit/s (PAM-4 48 × 28 GBaud PDM) aggregate data transmission capacity over 25 km of SSMF with error-free operation.

Mode transition in an oxygen low-pressure, very high frequency (162 MHz), multi-tile electrode capacitively coupled plasma

An experimental investigation of electrode voltage/discharge current, plasma density, including negative ions and ion flux, and ion energy distributions (IEDs) is performed in a low-pressure oxygen discharge excited by a multi-tile electrode, very high frequency (162 MHz) capacitively coupled plasma system. The results show a mode transition vs RF power. An inflection point is observed in the measured electrode voltage and current near to the mode transition. The negative ion density inferred from the measured electron density and ion flux using resonance hairpin probe and planar probe, respectively, shows an initial increase and then decrease after mode transition. The IED shows a symmetric narrow distribution and the mean energy first increases up to the transition point and then decreases with further increase in RF power. A change in the current coupling mechanism and variation in the discharge impedance due to the presence of negative ions are responsible for the observed mode transition.

Effects of discharge mode and gas composition for plasma‐hydrophilized titanium surface on hydrophilic sustainability

Plasma hydrophilization under various conditions was carried out on Ti substrates to investigate the effect of the applied parameters on the hydrophilic sustainability. The plasma was discharged from gases comprising Ar and/or O2 at various ratios using DC and RF modes. Notable differences in the surface morphology by the plasma conditions was hardly found, while the ratio of hydroxide on the surface was influenced by the discharge mode. The hydrophilicity was significantly improved regardless of the treatment conditions, that is, the gas composition and discharge mode. The deterioration of the hydrophilicity was occurred by storing in the ambient atmosphere or distilled water, wherein the deterioration in distilled water was suppressed when using DC as a discharge mode. The hydrophilicity was preserved when the specimens was stored in a physiological solution such as phosphate buffered saline solution due to the adsorption of Na+ and Cl− in the solution; its effect was far superior to that contributed by the parameter settings. In conclusion, plasma discharge mode enabled to improve the deterioration of hydrophilicity only slightly.

Dual frequency DBD: influence of the amplitude and the frequency of applied voltages on glow, Townsend and radiofrequency DBDs

To study dual frequency Townsend glow and radio frequency DBDs in an Ar/NH3 Penning mixture, different voltages are applied on each electrode of a plane/plane DBD. The one which has the higher amplitude and frequency, V H, determines the discharge regime. The other one, which has a lower amplitude and frequency, V L, is more similar to a bias voltage. V H frequency ranges from 50 kHz to 13.56 MHz and V L frequency from 1 kHz to 2 MHz. The amplitude of V L is always kept lower than the breakdown voltage. The discharge behavior is characterized by space and phase resolved optical emission spectroscopy and Fourier transform of the plasma induced light intensity. When the frequencies of two voltages are close to each other, V L higher than 150 V increases the discharge light intensity. In glow and Townsend discharges, this increase is attributed to the enhancement of the plasma density, due to the ions drift from the plasma bulk to the cathode, which produces a higher secondary electron emission. For the radiofrequency discharge, the enhancement of the light intensity is attributed to an enhancement of the positive space charge due to the higher voltage amplitude.When the frequencies of two voltages are very different, e.g. for V L between 1 and 100 kHz and a 5.5 MHz α-RF discharge, the behavior largely depends on V L amplitude. Above some low frequency (LF), the discharge tends to extinguish when V L amplitude is at its maximum. This is explained by a diminution of the plasma density resulting from the ion drift to the cathode due to V L. When V L is very high, it enhances the discharge intensity. This discharge amplification is associated with a transition from α to γ RF mode, which only occurs when the two voltages have the same polarity. Whatever the RF discharge mode, γ or α, the discharge is diffuse. To determine the interest of LF-RF dual frequency DBD for the PECVD, SiOx coatings, made with a single and a dual LF-RF frequency DBDs, are compared. It is concluded that the ɣ dual frequency removes OH functions from the material lattice and densifies the layer.

Simultaneous improvement of corrosion resistance and bioactivity of a titanium alloy via wet and dry plasma treatments

The fabrication of bioactive oxide layers on Ti–6Al–4V alloy by combining of wet and dry plasma methods for optimizing the chemical stability and biological activity together was reported. To achieve this goal, dry plasma sputtering depositions of Mg and Zn in the RF and DC modes, respectively, were performed for 5 and 20 min on the surface of titanium oxide obtained by wet plasma electrolytic oxidation of Ti–6Al–4V alloy substrate. Zn and Mg particles were successfully introduced into the titanium oxide layer which not only leads to decrease the fraction and size of microdefects but also increases the fraction of biocompatible anatase phase in compassion to that in the un-sputtered oxide layer. The corrosion resistance of sputtered oxide layers was superior to the un-sputtered layer. Regarding the hydroxyapatite formation and cell proliferation, Zn and Mg particles incorporated in less amounts in the sample sputtered for 5 min were of considerable significance in facilitating the nucleation and growth of hydroxyapatite and proliferation of MC3T3-E1 on the surface of this sample. Thus, the oxide layer containing Zn and Mg particles would be used as a promising implant material due to its great intrinsic chemical stability and osteointegration ability.