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761.
采用侵蚀失重法研究Ga、Al对Sn-9Zn钎料在3.5%NaCl水溶液中耐腐蚀性的影响.结果表明,添加Ga元素后,腐蚀产物的粘附性提高,均匀覆盖在钎料表面上,提高了钎料的耐蚀性能;添加Al以后,Zn和Al被选择性腐蚀,腐蚀随着Al含量的增加而加剧.采用热重分析(TGA)和俄歇电子能谱(AES)研究Ga、Al对Sn-9Zn钎料高温抗氧化性的影响.结果表明,Ga可在钎料表面形成一层集肤层;Al可在钎料表面形成一层致密的氧化膜,两者均可阻挡空气中的氧向钎料内部扩散,从而大大改善钎料的高温抗氧化性. 相似文献
762.
763.
采用恒电流法测定了添加Ga元素前后的Al-Zn-Bi系合金在人造海水中的开路电位、工作电位和电流效率,观察了该试验过程后合金的表面腐蚀形貌;利用极化曲线和电化学阻抗谱研究了该阳极合金在3.5%NaCl溶液中腐蚀过程的演变规律。结果表明:Ga能使Al-Zn-Bi系合金开路电位负移,工作电位稳定,电流效率升高,腐蚀形貌更加均匀;Ga可均匀固溶于铝合金中,并与回沉积的阳离子形成Ga基汞齐,使得阳极合金的活化控制步骤由第二相粒子优先溶解-脱落机理转变为金属阳离子的溶解-再沉积机理,促进阳极合金的均匀溶解,从而提高其综合电化学性能;等效电路RL(Cs(CpRp)(Q1Rd1)(LRa))和RL(Cs(CpRp)(Q1Rd1)(LRa)(Q2Rd2))能较好地表征两种合金的腐蚀行为和活化机理。 相似文献
764.
Mn-doped β-Ga2O3 (GMO) films with room-temperature ferromagnetism (RTFM) are synthesized by polymer-assisted deposition, and the effects of annealing atmosphere (air or pure O2 gas) on their structures and physical properties are investigated. The characterizations show that the concentrations of vacancy defects and Mn dopants in various valence states and lattice constants of the samples are all modulated by the annealing atmosphere. Notably, the samples annealed in air (GMO–air) exhibit a saturation magnetization as strong as 170% times that of the samples annealed in pure O2 gas (GMO–O2), which can be quantitatively explained by oxygen vacancy (VO)-controlled ferromagnetism due to bound magnetic polarons established between delocalized hydrogenic electrons of VOs and local magnetic moments of Mn2+, Mn3+, and Mn4+ ions in the samples. Our results provide insights into mechanism-based tuning of RTFM in Ga2O3 and may be useful for design, fabrication, and application of related spintronic materials. 相似文献
765.
We have developed an electrodeposition bath based on a buffer solution so that the stability of the electrodeposition process is enhanced and no metal oxides or hydroxides precipitate out of solution. The buffer-solution-based bath also deposits more gallium in the precursor films. As-deposited precursors are stoichiometric or slightly Cu-rich CuIn1−xGaxSe2. Only a minimal amount of indium was added to the electrodeposited precursor films by physical vapor deposition to obtain a 9.4%-efficient device. 相似文献
766.
混合合金法添加Ga对Nd—Dy—Fe—Co—B烧结磁体的磁性和微观结构的影响 总被引:2,自引:0,他引:2
对用混合合金法制备的Nd7.69Dy6.62Fe64.33Co14.83B6.53/Ga烧结磁体的磁性和微观结构进行了研究。结果表明:添加0.5%(质量分数)的Ga后;磁体的iHc由1232kA/m升高到1819kA/m,在200℃放置0.5h后的磁通不可逆损失由33.3%下降到5%以下,当Ga的添加量达到1.0%左右时,Ga的作用达到最大值,微观结构分析表明,不添加Ga磁体的晶粒边界,尤其是晶界角隅处多呈现弯曲和凹凸不平的形状,添加Ga磁体的晶粒边界则呈现平滑和近似直线的形状,烧结过程中Ga原子置换Nd2Fe14B相中Fe原子形成Nd2Fe14-xGaxB相,与此同时,被置换的Fe原子进入液相与富和Nd相、富B相反应形成新的Nd2Fe14B(或Nd2Fe14-xGaxB)相,这是导致磁体的磁性和微观结构发生变化的主要原因。 相似文献
767.
《分离科学与技术》2012,47(11):1673-1676
A chromatographic 68Ge/68Ga generator using nano zirconia as the sorbent matrix was developed to avail 68Ga in an organic medium for industrial radiotracer applications. Acetylacetone was used as the eluent for the extractive desorption of 68Ga ions from the sorbent phase. The effect of varying the amount of acetylacetone on 68Ga yield and achieving ideal experimental conditions were studied. The major advantage of this generator is its ability to deliver ready to use “industrial 68Ga tracer” with > 90% yield and high radionuclidic and radiochemical purity. The performance of the generator remained consistent on repeated elutions over a period of 1 year. 相似文献
768.
《Materials Science & Technology》2013,29(5):884-889
AbstractPhase diagram of the Bi–Ga–Sb ternary system has been investigated by DTA and SEM with EDS measurements. Phase transition temperatures in four vertical sections and isothermal section at 500°C were studied. Experimental results were compared with calculated phase diagram by the Calphad method. 相似文献
769.
《Calphad》2013
Thermodynamic modeling of the Ga–X (X=B, Ca, Sr, Ba) systems was performed based on the available experimental information and first-principles calculations. Enthalpies of formation for the compounds (Ca28Ga11, Ca5Ga3, Ca11Ga7, CaGa, Ca3Ga5, CaGa2, Ca3Ga8, CaGa4, Ga4Sr, Ga2Sr, Ga7Sr8, Ba8Ga7, BaGa2 and BaGa4) at 0 K were computed by ab initio methods, and were used to improve the accuracy of the present assessment. A set of self-consistent thermodynamic parameters was obtained. The computed phase diagrams and thermodynamic properties of the Ga–X (X=B, Ca, Sr, Ba) systems agree well with the experimental data and first-principles calculations. 相似文献
770.
《Progress in Photovoltaics: Research and Applications》2017,25(12):1068-1076
Recent breakthroughs in Cu(In,Ga)Se2 (CIGS) thin film solar cell energy conversion efficiency are related to the application of a potassium fluoride post‐deposition treatment (KF‐PDT) to the completed absorber. Using X‐ray photoelectron spectroscopy and Raman scattering, we compare CIGS layers prior and after the KF‐PDT in the case of a deterioration and an improvement of the solar cells photovoltaic performance. The purpose is to study and model the modification of the surface in both cases and address some of the required characteristics of the absorber, grown on soda lime glass by 3‐stage process, in order to take advantage of the treatment. We show that, in both cases, KF‐PDT induces the formation of GaF3, which is removed during the subsequent chemical bath deposition of CdS, explaining the Ga depleted absorber surface, already reported in literature. However, the presence or not of an ordered defect compound (ODC), correlated with the third stage duration during the CIGS growth, is shown to be crucial in the modifications of the surface induced by the treatment. When an ODC is present prior the treatment, KF‐PDT leads to the formation of a surface layer of In2Se3 containing K, and the photovoltaic performance of completed solar cells are improved. When no ODC is present prior KF‐PDT, no trace of K is found at the absorber surface after the treatment, copper (Cu) segregates into detrimental CuxSe phases, high amount of elemental Se is formed, and the photovoltaic performance are lowered. The role of the ODC during the KF‐PDT is finally discussed. 相似文献