White Light Emission from ZnS:Mn Thin Films Deposited on GaN Substrates by Pulsed Laser Deposition

ZnS：Mn thin films are grown on CaN substrates by pulsed laser deposition. The structure, morphology and optical properties are investigated by x-ray diffraction, scanning electron microscopy and photolumineseenee （PL）. The obtained ZnS：Mn thin films are grown in preferred orientation along β-ZnS （111） direction corresponding to crystalline structure of cubic phase. The deposition temperature has an obvious effect on the structure, surface morphology and optical properties of ZnS：Mn thin films. PL measurements show that there are two emission bands located at 44Ohm and 595 nm when the films are deposited at temperatures from 100℃ to 500℃. The relative integrated intensity of the blue emission and orange-red emission is determined by the deposition conditions. At the proper deposition temperature of 300℃, the color coordinate is closest to （0.33, 0.33）. The ZnS：Mn films on CaN substrates can exhibit white light emission.

Energy Stabilities, Magnetic Properties, and Electronic Structures of Diluted Magnetic Semiconductor Zn1-xMnxS（001） Thin Films

We investigate the electronic and magnetic properties of the diluted magnetic semiconductors Zn1-xMnxS（001） thin films with different Mn doping concentrations using the total energy density functional theory. The energy stability and density of states of a single Mn atom and two Mn atoms at various doped configurations and different magnetic coupling state were calculated. Different doping configurations have different degrees of p-d hybridization, and because Mn atoms are located in different crystal-field environment, the 3d projected densities of states peak splitting of different Mn doping configurations are quite different. In the two Mn atoms doped, the calculated ground states of three kinds of stable configurations are anti-ferromagnetic state. We analyzed the 3d density of states diagram of three kinds of energy stability configurations with the two Mn atoms in different magnetic coupling state. When the two Mn atoms are ferromagnetic coupling, due to d-d electron interactions, density of states of anti-bonding state have significant broadening peaks. As the concentration of Mn atoms increases, there is a tendency for Mn atoms to form nearest neighbors and cluster around S. For such these configurations, the antiferromagnetic coupling between Mn atoms is energetically more favorable.

Mn^(2+)促进Bacillus altitudinis LZP02生物膜形成

【目的】Bacillus altitudinis LZP02是一株水稻根际促生菌(PGPR),能定殖于水稻根部,形成生物膜,且Mn^(2+)对LZP02菌株生物膜形成具有促进作用,但调控机制尚不明确,旨在探究Mn^(2+)对LZP02菌株生物膜形成的促进机制。【方法】采用结晶紫染色法进行生物膜定量分析、蒽酮-硫酸法测定胞外多糖产量、扫描电镜(SEM)观察LZP02菌株在水稻根际定殖情况、转录组学测序技术分析差异表达基因(DEGs)。【结果】添加4 mmol/L Mn^(2+)和8 mmol/L Mn^(2+)显著提高了LZP02菌株的成膜能力和胞外多糖产量,扫描电镜发现4 mmol/L Mn^(2+)和8 mmol/L Mn^(2+)提高了LZP02菌株在水稻根际的定殖能力,随着Mn^(2+)浓度的增加,DEGs数量显著增多,其主要富集在芽孢形成、毒素代谢途径和双组分系统中。1 mmol/L Mn^(2+)和4 mmol/L Mn^(2+)处理组发现skf操纵子中基因的表达均上调。扫描电镜观察发现在1 mmol/L Mn^(2+)和4 mmol/L Mn^(2+)处理组中LZP02菌体存在损伤。4 mmol/L Mn^(2+)处理组双组分系统中KinE和Spo0A基因均显著上调。【结论】Mn^(2+)通过“嗜食同类”和双组分系统中KinE基因激活Spo0A~P提高了菌株LZP02的成膜能力。

Influence of low-temperature sulfidation on the structure of ZnS thin films

ZnS thin films were prepared by sulfuring zinc thin films at different sulfuration temperatures. The crystal structure,surface morphology, defects, and optical properties of the thin films were characterized by x-ray diffraction(XRD), scanning electron microscopy(SEM), positron annihilation Doppler broadening, and UV-Vis spectrophotometer, respectively.It was found that the(200)-plane preferred orientation of the ZnS thin films changed to(111)-plane with increasing sulfidation temperature. Moreover, a number of large holes were generated at 420?C and eliminated at 440?C. The concentration of defects was lowest when the sulfuration temperature was 440?C. The optical transmission of all samples was maintained at 60%–80% in the wavelength range of 400 nm–800 nm, and the band energy of the ZnS thin films was approximately3.5 e V for all treatment temperatures except 430?C.

Giant modulation of magnetism in(Ga,Mn)As ultrathin films via electric field

Taking the advantages of semiconducting properties and carrier-mediated ferromagnetism in(Ga,Mn)As,a giant modulation of magnetism via electric field in(Ga,Mn)As ultrathin film has been demonstrated.Specifically,huge interfacial electric field is obtained by using ionic liquid as the gate dielectric.Both magnetization and transport measurements are employed to characterize the samples,while the transport data are used to analyze the electric filed effect on magnetism.Complete demagnetization of(Ga,Mn)As film is then realized by thinning its thickness down to ~2 nm,during which the degradation of ferromagnetism of(Ga,Mn)As ultrathin film induced by quantum confinement effect is suppressed by inserting a heavily-doped p-type GaAs buffer layer.The variation of the Curie temperature is more than 100 K,which is nearly 5-times larger than previous results.Our results provide a new pathway on the efficient electrical control of magnetism.

采用高压固溶制备具有均匀腐蚀行为的高强度抗菌Zn-4Ag-Mn合金

采用高压固溶(HPS)法制备Zn-4Ag-Mn合金,获得高强度、可均匀降解、抗菌的植入材料。显微组织表征表明,HPS处理使Zn-4Ag-Mn合金晶粒比铸态(AC)合金的细化57.9%,其第二相平均尺寸减小到10.2μm。压缩、维氏硬度和磨损摩擦试验表明,HPS合金具有较高的力学性能,抗压屈服强度为333.5MPa,维氏硬度为Hv 89.5。电化学腐蚀和浸泡腐蚀试验表明,HPS处理优化合金的耐蚀性,使其腐蚀均匀。此外。经抗菌实验测试,HPS处理的Zn-4Ag-Mn合金具有优异的抗菌性能,抗菌率为71.6%。这些结果表明,HPS处理的Zn-4Ag-Mn是一种很有前途的生物可降解植入材料。

Corrosion characteristics of single-phase Mg-3Zn alloy thin film for biodegradable electronics

Biodegradable metals as electrodes, interconnectors, and device conductors are essential components in the emergence of transient electronics, either for passive implants or active electronic devices, especially in the fields of biomedical electronics. Magnesium and its alloys are strong candidates for biodegradable and implantable conducting materials because of their high conductivity and biocompatibility, in addition to their well-understood dissolution behavior. One critical drawback of Mg and its alloys is their considerably high dissolution rates originating from their low anodic potential, which disturbs the compatibility to biomedical applications. Herein, we introduce a single-phase thin film of a Mg-Zn binary alloy formed by sputtering, which enhances the corrosion resistance of the device electrode, and verify its applicability in biodegradable electronics. The formation of a homogeneous solid solution of single-phase Mg-3Zn was confirmed through X-ray diffraction and transmission electron microscopy. In addition, the dissolution behavior and chemistry was also investigated in various biological fluids by considering the effect of different ion species. Micro-tensile tests showed that the Mg-3Zn alloy electrode exhibited an enhanced yield strain and elongation in relation to a pure Mg electrode. Cell viability test revealed the high biocompatibility rate of the Mg-3Zn binary alloy thin film. Finally, the fabrication of a wireless heater demonstrated the integrability of biodegradable electrodes and highlighted the ability to prolong the lifecycle of thermotherapy-relevant electronics by enhancing the dissolution resistance of the Mg alloy.

Mn和Zn含量对无镍白铜性能的影响

通过改变Mn和Zn两种元素在合金中的含量来研究Mn和Zn对新型无镍白铜颜色和抗变色性能的影响。采用色差仪得到合金色度参数,通过光学显微镜观察合金金相组织,通过硬度试验检测力学性能,通过盐水腐蚀试验获得合金抗变色性能,最后通过与BZn18-8锌白铜的颜色进行对比来确定新型无镍白铜配方。实验结果表明,Zn含量增加可以降低合金中红色成分增加合金中黄色成分,但对合金抗变色性能影响不大,Mn含量的增加会起到漂白合金颜色的作用,同时也会降低合金的抗变色性能。

热处理对压铸Mg-Zn-Al-Mn合金组织及性能的影响

采用压铸成形工艺制备Mg-Zn-Al-Mn合金,研究不同热处理工艺对压铸Mg-Zn-Al-Mn合金力学性能和显微组织的影响。结果表明,压铸态合金采用直接时效处理时,在190℃下直接时效5 h,合金强度达到峰值,其抗拉强度、屈服强度和伸长率分别为236 MPa,149 MPa和7.3%。经过固溶处理后,过饱和固溶度提升,大部分第二相颗粒在固溶过程中溶解进镁基体中,即有更大的第二相脱溶析出驱动力。335℃×4 h+190℃×5 h时合金力学性能达到最佳,其抗拉强度、屈服强度和伸长率分别为243 MPa,167 MPa和5.1%。浸泡试验表明,经过T6处理后的合金具有最好的耐浸泡腐蚀性能,电化学试验结果显示,T6处理合金具有最小的腐蚀电流密度和最大的高频阻抗弧半径,表明其具有最优的耐腐蚀性能。

Crystallization behavior of Ni_(54)Mn_(25.1)Ga_(20.9) ferromagnetic shape memory thin film

NiMnGaferromagnetic shape memory thin film was deposited onto Al foil using r.f.magnetron sputtering technique.The crystallization behavior of the film was investigated by XRD and DSC.The activation energy of crystallization of the film was calculated by Kissinger’s method.The results show that the crystallization temperature of NiMnGafree-standing thin film in martensite state is 372 ℃,and the activation energy of crystallization is about 191.9 kJ·mol-1.

Preparation,structure and ferromagnetic properties of the nanocrystalline Ti_(1-x)Mn_xO_2 thin films grown by radio frequency magnetron co-sputtering

This paper reported that the Mn-doped TiO2 films were prepared by radio frequency （RF） magnetron cosputtering. X-ray diffraction measurements indicate that the samples are easy to form the futile structure, and the sizes of the crystal grains grow big and big as the Mn concentration increases. X-ray photoemlssion spectroscopy measurements and high resolution transmission electron microscope photographs confirm that the manganese ions have been effectively doped into the TiO2 crystal when the Mn concentration is lower than 21%. The magnetic property measurements show that the Ti1-xMnxO2 （x = 0.21） films are ferromagnetic at room temperature, and the saturation magnetization, coercivity, and saturation field are 16.0 emu/cm^3, 167.5 × 80 A/m and 3740 × 80 A/m at room temperature, respectively. The room-temperature ferromagnetism of the films can be attributed to the new futile Ti1-xMnxO2 structure formed by the substitution of Mn^4＋ for Ti^4＋ into the TiO2 crystal .lattice, and could be explained by O vacancy （Vo）-enhanced ferromagnetism model.

Study on Microcrystaline Structure and Luminescence of ZnS Thin Film Devices

The Electroluminescence thin films of zinc sulfide do ped with erbium, fabricated by thermal evaporation with two boats, are analyzed by the technology of X-ray diffraction (XRD) and X-ray photoelectron spectrosc opy (XPS). The relationship between electroluminescence brightness and microst ructure of the thin films is obtained. The analysis results of XRD indicate th at the fabricated zinc sulfide thin films belong to the blende structure and hav e a trend of preferential orientation. The XPS measurements reveal the surface m icrostructure states formed mainly by oxygen absorption and carbon absorption th at effect on the EL excitation and relaxation luminescence process. The maximum photoelectron peak corresponding to the doped erbium is detected at a depth of 1 35nm to 350nm that formed the activation layer in the films. Analysis shows that the high brightness of the film devices is attributed to the crystalline planes of growth orientated in the (311), (400). In explanation of this phenomenon, th e status of the substitute energy for Er 3+ replacing Zn 2+ in the hos t lattice of zinc sulfide is discussed. All results of describing above are referable in researching of the electroluminescence excitation machnism of the t hin film devices and in favor of fabricating the thin film devices with high qua lity.

电力金具表面电沉积Zn-Mn合金镀层及其耐蚀性能研究

Zn镀层是一种常见的防腐涂层,可作为牺牲阳极为电力金具提供良好的阴极保护。电沉积制备的Zn合金镀层可进一步提高镀层的耐蚀性,为电力金具提供更为有效的防护。采用X射线衍射、扫描电子显微镜、动电位极化曲线和电化学阻抗谱分别对Zn-Mn合金镀层的物相、微观形貌和耐蚀性能进行了表征,研究了镀液中MnSO_(4)·H_(2)O的含量对Zn-Mn合金镀层的影响。结果表明,Zn-Mn合金镀层在3.5 wt.%NaCl溶液中具有明显的钝化特征,其腐蚀电流密度低于纯Zn镀层,电化学阻抗值大于纯Zn镀层。当镀液中的MnSO_(4)·H_(2)O的含量为33.8g/L时,所制备的Zn-Mn合金镀层(Zn-Mn Ⅱ)具有平整致密的表面形貌和较高的Mn含量,其耐蚀性能最好。

Bipolar Resistive Switching in Epitaxial Mn_3O_4 Thin Films on Nb-Doped SrTiO_3 Substrates

Spinel （O01）-orientated Mn304 thin films on Nb-doped SrTi03 （001） substrates are fabricated via the pulsed laser deposition method. X-ray diffraction and high-resolution transmission electron microscopy indicate that the as-prepared epitaxial fihn is well crystaiHzed. In the film plane the orientation relationship between the film and the substrate is [lOOjMn3 04 ｜｜[110] Nb-doped SrTiO3. After an electroforming process, the film shows bipolar nonvolatile resistance switching behavior. The positive voltage bias drives the sample into a low resistance state, while the negative voltage switches it back to a high resistance state. The switching polarity is different from the previous studies. The complex impedance measurement suggests that the resistance switching behavior is of filament type. Due to the performance reproducibility and state stability, Mn3O4 might be a promising candidate for the resistive random access memory devices.

Synthesis of Cu_2ZnSnS_4 thin film from mixed solution of Cu_2SnS_3 nanoparticles and Zn ions

The Cu2ZnSnS4 thin film was prepared by a facile solution method without vacuum environment and toxic substance. The formation mechanism of the film was studied by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Raman scattering measurements. Through cyclic voltammetry and photo-electricity tests, the electrocatalytic activity of the prepared film as the counter electrode of dye-sensitizedsolar cell was also studied. The results show that the mixed precursor solution mainly consists of Cu2SnS3 nanoparticles and Zn ions.After 550 °C annealing process on the precursor film prepared from the mixed solution, Cu2ZnSnS4 thin film is obtained. Besides, itis found that the prepared Cu2ZnSnS4 thin film has the electrocatalytic activity toward the redox reaction of I3?/I? and the dye-sensitized solar cell with the prepared Cu2ZnSnS4 thin film as the counter electrode achieves the efficiency of 1.09%.

Near Infrared Electroluminescence of Er-doped ZnS Thin Film Devices

Near infrared electroluminescence characteristics of the Er-doped ZnS thin film devices,fabricated by thermal evaporation with two boats, are reported. The study of the film microstructure has been carried out using X-ray diffraction. The effects of the Er-doped film microstructure on luminescence are pointed out.

Electric-Field Tunability of Dielectric in Polycrystalline Sr1-xMnxTiO3 Thin Films

The electric-field tunability of dielectric constant （ε-E） in Sr1-xMnxTiO3 films （x = 0, 0.005, 0.010, 0.020 and 0.030） prepared by the metal organic decomposition method on Pt/Ti/SiO2/Si substrates is studied in the frequency range from 100Hz to 1MHz with different Mn contents at different temperatures. The frequencyindependent tunability increases strongly with decreasing the temperature from 300 K to 150K. The tunability （-31%） in thin films （x = 0.005） at 150K is obtained and the temperature for the same tunability in ceramics is about 60 K lower than the present one. This tunability is comparable with that in one of ferroelectric Sr1-1.sxBixTiO3 thin films. Similarly, the well-defined P（E） hysteresis 10013 and 2Pr （1.2 μC/cm^2） can be obtained at 300 K in Sr1-xMnxTiO3 films with z = 0.005. Both the existence of electric dipole or poled micro domain introduced by the doped Mn2＋ located in the off-center position at Sr sites and the strain between the thin film and the substrate are the origins of the tunable and polar behavior in Sr1-xMnxTiO3 films.

X-Ray Radiation Sensing Properties of ZnS Thin Film:A Study on the Effect of Annealing

Chemically synthesized ZnS thin film is found to be a good x-ray radiation sensor. We report the effect of annealing on the x-ray radiation detection sensitivity of a ZnS thin film synthesized by a chemical bath deposition technique. The chemically synthesized ZnS films are annealed at 333, 363 and 393K for 1 h. Structural analyses show that the lattice defects in the films decrease with annealing. Further, the band gap is also found to decrease from 3.38 to 3.21 eV after annealing at 393K. Current-voltage characteristics of the films are studied under dark and x-ray irradiation conditions. Due to the decrease of lattice defects and band gap, the conductivity under dark conditions is found to increase from 2.06 × 10^-6 to 1.69 × 10^-5 S/em, while that under x-ray irradiation increases from 4.13 × 10^-5 to 5.28 ×10^-5 S/cm. On the other hand, the x-ray radiation detection sensitivity of the films is found to decrease with annealing. This decrease of detection sensitivity is attributed to the decrease of the band gap as well as some structural and surface morphological changes occurring after annealing.

Al-Zn-Mn-Si-Mg系压铸铝合金阳极氧化工艺

在传统铝合金阳极氧化电解工艺基础上,添加草酸、酒石酸和柠檬酸等形成硫酸-有机酸混合体系氧化处理液,对Al-Zn-Mn-Si-Mg系压铸铝合金进行阳极氧化处理,探索阳极氧化工艺参数和有机酸种类对氧化膜微观形貌、耐腐蚀和耐磨性能的影响.研究结果表明:在硫酸质量分数为10%、氧化电压为18V、氧化时间为60 min、氧化温度为20℃的条件下,与纯硫酸体系相比,混合酸体系能显著增加Al-Zn-Mn-Si-Mg系压铸铝合金阳极氧化膜厚度,提高氧化膜的耐腐蚀性能和耐磨性能;其中10%硫酸-15%柠檬酸混合体系(百分数均为质量分数,下同)下的氧化膜耐腐蚀性能较强,10%硫酸-10%酒石酸体系下的氧化膜耐磨性能较优.

Zn-Al共掺杂和形貌调控制备LiMn_(2)O_(4)正极材料及其电化学性能

采用固相燃烧法在不同焙烧温度(600、650、700和750℃)下制备了LiZn_(0.05)Al_(0.03)Mn_(1.92)O_(4)正极材料,采用XRD、SEM、XPS对其进行了表征,通过循环伏安(CV)和电化学阻抗(EIS)测试了其电化学性能。结果表明,Zn-Al共掺杂和焙烧温度未改变LiMn_(2)O_(4)的晶体结构,正极材料的结晶性随焙烧温度(<750℃)的升高而增加,650℃及以上时形成了较多包含高暴露(111)晶面、小面积(110)、(100)晶面的截断八面体形貌晶粒,但750℃时正极材料发生部分分解。焙烧温度650℃的样品(LZAMO-650)表现出最佳的电化学性能,在5 C和10 C倍率下,初始放电比容量分别为101.3、99.9 mA·h/g,循环1000圈后容量保持率分别为81.5%、74.3%;LZAMO-650样品极化作用较小,有较好的循环可逆性,具有较低的电荷转移阻抗(R_(ct)=132.14Ω)和较大的锂离子扩散系数(DLi^(+)=3.65×10^(–16)cm^(2)/s)。Zn-Al共掺杂和形貌调控改性LiMn_(2)O_(4)正极材料有效抑制了Jahn-Teller效应,形成的截断八面体颗粒形貌降低了Mn的溶解,同时提供了更多的Li^(+)迁移三维通道,从而改善了材料的电化学性能。