Supercapacitive properties of manganese nitride thin film electrodes prepared by reactive magnetron sputtering: Effect of different electrolytes

Development of metal nitride-based thin film binder-free electrodes is a rapidly emerging area of research for the development of supercapacitors. The manganese nitride (Mn₃N₂) binder-free thin film electrodes were prepared using DC magnetron sputtering process. X-ray diffraction and the Raman spectroscopy characterization confirmed the formation of the tetragonal phase of Mn₃N₂ thin film. Field emission scanning electron microscopy revealed that the Mn₃N₂ particles are in nanoscale range and the particles with pyramidal shape are distributed uniformly on the surface of the film. Further, the Mn₃N₂ electrodes were examined by cyclic voltammetry and galvanostatic charge-discharge measurements to investigate the supercapacitive properties. The electrochemical measurements were performed on Mn₃N₂ deposited on conducting stainless steel substrates in different electrolytes (KOH, KCl and, Na₂SO₄ at 1 M concentration). The effect of various electrolytes on the areal capacitance, cycling stability, capacitance retention of the Mn₃N₂ electrodes was investigated. The Mn₃N₂ electrodes show high areal capacitance of 118 mF cm⁻² for KOH, 68 mF cm⁻² for KCl and 27 mF cm⁻² for Na₂SO₄ at a scan rate of 10 mV/s. Moreover, the Mn₃N₂ electrodes indicated excellent cycling stability with capacitance retention of 98.5%, 89% and 83% for KOH, KCl, and Na₂SO₄, electrolytes respectively after 4,000 cycles. A comparative study on the electrochemical supercapacitive properties of the Mn₃N₂ electrode in different aqueous electrolytes is reported for the next generation electrochemical energy storage devices.     

首饰基材表面反应磁控溅射SiO2薄膜工艺

采用反应磁控溅射工艺在S950首饰基材表面沉积防指纹用的SiO2薄膜,研究了氧气流量、氧气体积分数、溅射电流和沉积时间对沉积速率和薄膜化学组成的影响.结果表明,膜层沉积速率随着溅射电流增大而快速增加,随着氧气流量增加而先升后降,随着氧气体积占比增加而先略升后稳定,随着镀膜时间的延长而略降.膜层的氧硅原子比随着氧气流量增...     

Sandwich-structured ZnO-MnO2-ZnO thin film varistors prepared via magnetron sputtering

ZnO varistors are widely used to protect electronic circuits form transient voltages. However, it is difficult to prepare varistors with voltage less than 10 V using ZnO ceramics. Here we prepared a ZnO-MnO₂-ZnO (ZMZ) sandwich thin film via magnetron sputtering and subsequent annealing at 200-500 °C. With the increase of annealing temperature, the manganese oxide sandwich layer reacts with the upper and lower ZnO layer and becomes thinner. After annealed at 500 °C, because of ZnO grain growth, the upper and lower ZnO layers joined together. The electrical properties of ZMZ films annealed at 400 °C show strong nonlinear I-V characteristics. A ZMZ low voltage thin film varistor with planar boundary potential barrier was obtained whose nonlinear coefficient α and varistor voltage V1 mA are about 30 and 6.0 V, respectively. The stable and excellent nonlinear characteristics make it a promising candidate for overvoltage protection in low operating voltage circuits.     

As-deposited LiCoO2 thin film cathodes prepared by rf magnetron sputtering

LiCoO₂ thin films were deposited using radio frequency (rf) magnetron sputtering system on stainless steel substrates. Different rf powers, up to 150 W, were applied during deposition. The as-deposited films exhibited (1 0 1) and (1 0 4) preferred orientation and the nanocrystalline film structure was enhanced with increasing rf power. The film crystallinity was examined using X-ray diffraction, Raman scattering spectroscopy and transmission electron microscopy. The compositions of the films were determined by inductively coupled plasma-mass spectroscopy. The average discharge capacity of as-deposited films is about 59 μAh/(cm² μm) for cut-off voltage range of 4.2 and 3.0 V. From the electrochemical cycling data, it is suggested that as-deposited LiCoO₂ films with a nanocrystalline structure and a favorable preferred orientation, e.g. (1 0 1) or (1 0 4) texture, can be used without post-annealing at high temperatures for solid-state thin film batteries.     

Study of the thermal stability of carbon nitride thin films prepared by reactive magnetron sputtering

CN_x amorphous films have been prepared by reactive magnetron sputtering in a pure N₂ discharge. The films grown on NaCl have been characterised by Fourier transform infrared spectroscopy (IR), transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). C/N atomic ratios have been determined by EELS with values in the range 2.0–1.2 for samples grown under different conditions. The thermal stability of the films upon heating in vacuum was followed ‘in situ’ at the transmission electron microscope by EELS. This study has been completed by a thermogravimetric and mass spectrometer analysis of evolved gases upon heating in nitrogen flow and vacuum, respectively. Under these conditions the films are stable up to 1023 K. Above this temperature the films decompose by elimination of nitrogen remaining a carbonaceous residue. The thermal stability of the films upon annealing in air was studied by following the evolution of the X-ray photoelectron spectroscopy (XPS) peaks during heating in air of films grown on steel. Deconvolution analysis of the XPS spectra allows to determine the evolution of the different type of bonds. In particular pure carbon in the films appears more reactive to oxygen than CN and C–N bonds.     

Heteroepitaxial growth of TiN film on MgO (100) by reactive magnetron sputtering

TiN thin films were deposited on MgO (100) substrates at different substrate temperatures using rf sputtering with Ar/N₂ ratio of about 10. At 700°C, the growth rate of TiN was approximately 0.05 μm/h. The structural and electrical properties of TiN thin films were characterized with x-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Hall measurements. For all deposition conditions, XRD results show that the TiN films can be in an epitaxy with MgO with cube-on-cube orientation relationship of (001)_TiN // (001)_MgO and [100]_TiN // [100]_MgO. TEM with selected-area electron diffraction pattern verifies the epitaxial growth of the TiN films on MgO. SEM and AFM show that the surface of the TiN film is very smooth with roughness approximately 0.26 nm. The minimum resistivity of the films can be as low as 45 μΩ cm.     

铝锰合金表面直流反应磁控溅射制备氧化铟锡薄膜

采用直流反应磁控溅射在AlMn合金表面制备出ITO薄膜.采用扫描电镜、X射线衍射、紫外-可见光测试、磨损试验、盐雾试验、薄膜厚度测量和显微硬度试验等方法对制备的ITO薄膜表面进行检测分析.结果表明:在溅射功率210 W、衬底温度120℃、溅射时间20 min的条件下,AlMn合金表面的ITO薄膜晶粒尺寸细小,与基底结合良好,AlMn合金表面光泽度好,强度、硬度高,并具有一定的耐磨、耐蚀性能.     

Li-ion diffusion kinetics in LiFePO4 thin film prepared by radio frequency magnetron sputtering

LiFePO₄ thin films were prepared by radio frequency (RF) magnetron sputtering and were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and atomic force microscope (AFM). Li-ion chemical diffusion coefficients, , were measured by potentiostatic intermittent titration technique (PITT), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The effects of Ag content, film thickness, and film orientation on the electrochemical performance and Li-ion chemical diffusion coefficients of the LiFePO₄ thin films were investigated. values were measured using the liquid electrolyte and the solid electrolyte, and the obtained values were discussed. The values by PITT and EIS were in the range of 10⁻¹⁴ to 10⁻¹² and 10⁻¹⁵ to 10⁻¹² cm² s⁻¹, respectively and that by CV was in the order of 10⁻¹⁴ cm² s⁻¹.     

磁控溅射制备高熵氧化物薄膜的阻挡扩散性能

利用磁控溅射在Ni–8at%W合金基体表面沉积(CoCrNiTa)O_x高熵氧化物薄膜,研究了它在1 000℃、100 h的真空扩散条件下的高温稳定性及其阻挡Ni–30at%Cr涂层与Ni–8at%W合金基体中元素互扩散的性能,采用X射线衍射仪、扫描电子显微镜、能谱仪、纳米压痕仪及划痕仪对薄膜进行研究。结果表明：(CoCrNiTa)O_x高熵氧化物薄膜较为致密,为非晶结构。随着溅射时间延长,薄膜纳米硬度上升的趋势很小,但膜基结合力增幅较大。(CoCrNiTa)O_x扩散障具有较好的高温稳定性,对Cr元素具有较好的扩散阻挡性能。     

Study the effect of thermal annealing on adhesion strength of Silver-Tantalum Oxide thin film deposited by reactive magnetron sputtering

Stainless steel (SS) are extensively used for healthcare, hygiene and surgical applications due to their excellent corrosion resistance and adequate mechanical strength. Among this class SS 316?L is employed most widely, due to highest corrosion resistance, good mechanical properties, resistance to sensitization and ease of fabrication. To incorporate antimicrobial characteristic in SS 316?L based surgical tools a nanocomposite layer comprising of Silver (Ag) and Tantalum oxide (Ta_xO_x) has been deposited by using Physical Vapor Deposition (PVD) magnetron sputtering. Delamination of ceramic layers on SS 316?L substrate is one of the major limitation arising from insufficient crystallization and poor adhesion strength. PVD magnetron sputtering has been employed to develop 5.49?µm thick Ag-Ta_xO_x nanocomposite layer on SS 316?L. Substantially improved adhesion strength has been achieved by controlling thermal treatment. The microstructure, surface and phase analysis of as-sputtered and annealed thin films has been carried out to determine the characteristics of the developed layer. A nanocomposite layer on SS 316?L substrate comprising of Ag and Ta_xO_x has been achieved by releasing O₂ during deposition. Thermal treatment was performed at 300, 400, 500 and 600?°C which progressively increased the crystallinity and segregation of Ag at the surface. Highest adhesion strength was achieved by annealing the coated samples at 400?°C, which exhibited four-fold increased adhesion strength when compared to as-deposited layer. The precipitation of a new phase Silver tantalum oxide (AgTaO₃) was observed for the samples annealed at temperature above 400?°C, which may be responsible for the decrease in adhesion strength.     

Luminescence properties of terbium-doped SiCN thin films by rf magnetron reactive sputtering

Terbium-doped SiCN (SiCN:Tb) thin films were deposited by rf magnetron reactive sputtering at 800 °C. The as-prepared samples were characterized by XRD, FTIR, and XPS. The results showed that SiCN:Tb films mainly contained both SiC and Si₃N₄ nano-compositions with complicated chemical bond networks. Photoluminescence measurements indicated that the undoped SiCN films exhibited a blue-green light emission, while SiCN:Tb films emitted a strong green one. The SiC nanocrystallites formed in the undoped SiCN films might be responsible for the blue-green light emission, while the formed quaternary Si-C-Tb-O compositions in the doped samples could account for the strong green PL behaviors.     

Structural and mechanical properties of CNx thin films prepared by magnetron sputtering

In an attempt to define the role of nitrogen in CN chemical bonding and in the formation of CN_x thin films, several coatings with a variable concentration of N₂ were grown onto (100) Si substrates using magnetron sputtering in N₂/Ar discharge. The chemical composition of the as-deposited films was investigated by means of Rutherford backscattering spectroscopy (RBS) and showed an [N]/[C] ratio up to 0.7. Raman and Fourier transform infrared (FTIR) spectroscopy were carried out to measure the optical vibration properties for studying the bonding state of nitrogen.By means of grazing incidence X-ray diffraction (XRD) and transmission electron microscopy (TEM) electron diffraction the structure of the deposited films was proven to be mainly amorphous containing small crystallites of CN_x compounds. Scanning tunneling microscopy (STM) shows the clusterlike surface of the films where the cluster size is characterized by scaling behaviour. The mechanical properties of the CN_x thin films adhering their substrates were investigated using the nanoindentation technique. From the load–displacement curve the hardness H and the Young's modulus E of the films were calculated.The relationships between deposition parameters and properties of CN_x films are shown and discussed. In particular, the influence of the applied r.f. power and the role of the N₂ partial pressure are demonstrated.     

Corrosion performance of thin hydrogenated amorphous carbon films prepared by magnetron sputtering

Hydrogenated amorphous carbon (a-CH_x) films were prepared by magnetron sputtering at different H₂/Ar gas flow ratios. Several sets of perpendicular magnetic recording disks with a-CH_x overcoats of 5 nm were prepared for accelerated environmental corrosion test. The corrosion spots on the disks and the corrosion products were analyzed using optical surface analyzer and time-of-flight secondary ion mass spectroscopy, respectively. Other techniques, such as Raman spectroscopy, atomic force microscopy nano-scratch and contact angle measurement, were used to characterize the properties of a-CH_x films. Compared to pure carbon overcoat, all the a-CHx overcoats have better corrosion resistance and higher polar component of surface free energy. The a-CH_x film with appropriate H content shows the highest scratching resistance, and the corresponding disk has the lowest corrosion area on the disk surface after the accelerated corrosion.     

CBD方法制备的Zn(O,S)薄膜的微结构表征及性能

对低温化学浴沉积方法制备的Zn（O,S）薄膜进行了研究,通过XPS、SEM、XRD、拉曼光谱、PL谱、紫外-可见吸收光谱等手段对薄膜的形貌、结构及组成进行系统表征,探究了其作为钙钛矿电池电子传输层的可能性。研究表明：化学浴沉积（CBD）方法制备的Zn（O,S）薄膜为ZnO、ZnS和ZnOS合金的复合膜;该薄膜对CH₃NH₃PbI₃光吸收层具有与TiO₂相当的电子抽提能力,是一种可供选择的高效柔性钙钛矿电池电子传输层材料。     

Structure and high-temperature tribological properties of Pb-Cr-O composite films prepared by reactive magnetron sputtering

The formation of ternary composite oxides in a high-temperature environment has laid the foundation for the design of high-temperature wear-resistant self-lubricating film. A series of Pb-Cr-O films with different Cr contents were prepared by incorporating different ratios of Pb-Cr into a target in the reactive magnetron sputtering system. The results showed that the hardness of the Pb-Cr-O films is greatly improved compared to the pure Pb-O film. In addition, the Pb₂₉Cr₄O₆₇ film with the highest Cr content forms an amorphous structure due to the accumulation of Cr⁶⁺ at the grain boundary, which improves the H/E and H³/E² of the film. At 600 °C, in contrast with the single PbO lubricating phase formed by pure Pb₃₃O₆₇ film, the Pb₂₉Cr₄O₆₇ film forms a composite lubricating phase of Pb₅CrO₈ and PbO. This leads to a decreased wear rate as low as 7.2 × 10^?6 mm³N^?1m^?1 while maintaining low coefficient of friction comparable to pure Pb₃₃O₆₇ film. At higher temperature of 700 °C, Cr element in Inconel 718 matrix diffuses into the Pb-based oxide film and forms Pb₅CrO₈ phase similar to Pb₂₉Cr₄O₆₇ film, which improves the wear resistance of the Pb₃₃O₆₇ film while maintaining low friction coefficient of 0.15.     

Dielectric enhancement of BaSrTi1.1O3/BaSrTi1.05O3/BaSrTiO3 multilayer thin films prepared by RF magnetron sputtering

BaSrTi_1.1O₃/BaSrTi_1.05O₃/BaSrTiO₃ multilayer (BSTM) thin films and BaSrTiO₃ (BST) thin films were deposited on LaNiO₃ (LNO)/SiO₂/Si substrates by radio frequency (RF) magnetron sputtering at substrate temperature of 400 °C, respectively. X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) investigations revealed that all the films have uniform and crack-free surface morphology with a perovskite structure. The dielectric constant of the BSTM thin films was increased and dielectric loss was decreased compared with those of uniform BST thin films. The dielectric constant of 420, dielectric loss of 0.017, and dielectric tunability of 38% were achieved for the BSTM thin films.     

Structural and electrochemical impedance spectroscopic studies on reactive magnetron sputtered titanium oxynitride (TiON) thin films

Titanium oxynitride films were deposited onto commercially pure titanium substrates by direct current reactive magnetron sputtering method using Ti targets and an Ar–N₂–O₂ mixture discharge gas. The X-ray photoelectron spectroscopy survey spectra on the etched surfaces of TiON films exhibited the characteristic Ti 2p, N 1s, and O 1s peaks at the corresponding binding energies 454.5, 397.0, and 530.7 eV, respectively. The surface topography of these coatings was studied using atomic force microscopy. The characteristic Raman peaks at 200 and 641 cm⁻¹ for the TiN bonds and at 148, 398 ,and 518 cm⁻¹ for the TiO₂ bonds were observed from the Laser Raman spectrometer. The potentiodynamic polarization studies in simulated bodily fluid were performed and the results are reported in this article.     

Electronic phase transition in CrN thin films grown by reactive RF magnetron sputtering

Chromium nitride thin films were prepared by reactive radio frequency magnetron sputtering on glass and Si(001) substrates. Thin films were grown at different nitrogen to argon flow rate ratio and their effect on the film composition, band gap and electronic phase transition was studied by different experimental technique. X-ray diffraction analyses establish that CrN films predominantly grow in [111]_CrN and [002]_CrN directions irrespective of the substrates used for the growths. The band gap was found to vary with the composition of the films. All films are semiconducting at room temperature and show discontinuity in their resistivity versus temperature curve indicating electronic transition. But the low temperature electronic phase depends on the growth conditions and composition of the films.     

溶胶-凝胶法制备疏水型SiO2薄膜的研究

采用溶胶-凝胶工艺,以正硅酸乙酯（TEOS）为前驱体,结合三甲基氯硅烷（TMCS）对胶粒的修饰作用,利用浸渍提拉法在玻璃表面制备了具有一定疏水能力的SiO2薄膜.考察了TMCS的掺杂量、醇硅比、加水量及热处理温度对薄膜疏水性的影响.