首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
电镀及化学镀磁记录介质薄膜的最新进展   总被引:2,自引:0,他引:2  
安茂忠  杨哲龙 《电化学》1997,3(1):92-98
本文综述了近年来国外电镀及化学镀磁记录介质薄膜的最新研究进展、电镀及化学镀镀液组成、工艺条件及其对薄膜性能的影响、存在问题及发展方向等.磁记录介质薄膜的制备,过去一直采用溅射方法,近年来国外开展了电镀及化学镀方法制备的研究.电镀方法包括水溶液电镀(如:Ni-Fe、Fe-Co合金等)和非水溶液电镀(如Tb-Fe、Nd-Fe、Tb-Fe-Co合金等),化学镀则是在Ni-P、Co-P合金的基础上,通过添加其它金属盐,得到磁记录介质薄膜,如:Co-Ni-P、Co-W-P、Co-Mn-P、Co-Ni-Re-P合金等  相似文献   

2.
Pd(Ⅱ)、Pt(Ⅱ)DMAF配合物已合成,并已定结构。本文采用MX2(M-Ni(Ⅱ),Co(Ⅱ),Zn(Ⅱ)、Cu(Ⅱ);X=Cl,Br,I)在CH2Cl2中和DMAF作用合成[MX2.2DMAF]型配合物。由NiCl2.2DMAF.C7H8晶胞参数推知属于对称链状四配位结构。IR谱表明,该化合物化学式为MX2.2DMAF。CV表明配合物中M(Ⅱ)和Fe(Ⅱ)存在。由于金属离子互相影响。Ep/2  相似文献   

3.
Pd(Ⅱ)、Pt(Ⅱ)DMAF配合物已合成,并已定结构[1].本文采用MX2(M=Ni(Ⅱ),Co(Ⅱ),Zn(Ⅱ),Cu(Ⅱ);X=Cl,Br,Ⅰ)在CH2Cl2中和DMAF作用合成[MX2·2DMAF]型配合物.由NiCl2·2DMAF·C7H8晶胞参数推知属于对称链状四配位结构.IR谱表明,该化合物化学式为MX2·2DMAF.CV表明配合物中M(Ⅱ)和Fe(Ⅱ)存在.由于金属离子互相影响,Ep/2随M(Ⅱ)性质呈规律性变化.  相似文献   

4.
ANOVELREACTIONBETWEENGe-GeANDFe-FeBONDSINCOMPLEX(Me_2GeGeMe_2)[(η~5-C_5H_4)Fe(CO)]_2(μ-CO)_2ANDCRYSTALSTRUCTUREOFTHEPRODUCT¥XiuT?..  相似文献   

5.
ELECTRON-TRANSFERINPOLYNUCLEARCYANO-BRIDGEDCOMPLEXOFTHETYPE[Co(Ⅲ)L_3-μ-Nc-FeⅡ)(CN)_5]~-(L=en)ShuZhongZHAN;XiaoYuanCHEN;QingJin?..  相似文献   

6.
通过Fe3(CO)(12)、硫醇(硫酚)和EtMgBr所形成的络盐[(μ-CO)(μ-RS)Fe2(CO)6]-Mg+Br与氯代芳酰氯的原位反应,合成了通式为(μ-RS)(μ-o-ClC6H4CO)Fe2(CO)6和(μ-RS)(μ-m-ClC6H4CO)Fe2(CO)6(R=n-Ru,t-Bu,Ph)的6个新桥芳酰基铁硫配合物,并用C/H分析、IR和1HNMR表征了它们的结构。  相似文献   

7.
标题化合物(Me_2SiSiMe_2)[η ̄5-(3-Me_3SiC_5H_3)Fe(CO)_2]_2/(μ-CO)_2(A)分子中的Fe-Fe键被钠汞齐还原断裂,生成相应的双铁负离子,分别与MeCOCl、PhCOCl、PhCH_2Cl、ClCH_2COOC_2H_5和Ph_3SnCl进行亲核取代反应,生成在铁原子上引入相应取代基的产物(Me_2SiSiMe_2)[η ̄5-(3-Me_3SiC_5H_3)Fe(CO)_2R]_2(R:MeCO(1),PhCO(2),PhCH_2(3),CH_2COOC_2H_5(4),Ph_3Sn(5),I(6))。A在氯仿中与碘反应,得到Fe-Fe断裂的双铁碘化物,但在苯中与过量碘反应,则得到Fe-I-Fe桥联的离子型化合物(Me_2SiSiMe_2)[η ̄5-(3-Me_3SiC_5H_3)Fe(CO)_2]_2I·I(7)。化合物6的晶体和分子结构经X射线衍射测定,6属单斜晶系,P21/c空间群,a=1.7217(4)nm,b=0.7753(2)nm,C=1.3629(7)nm,β=103.80(3)°,V=1.767(2)nm3,Z=4,Dc=1.6299·cm-1,最终偏差因子R=0.054。  相似文献   

8.
在550~90cm~(-1)波数范围内,测量簇阴离子[Cl_2FeS_2MS_2M′(PPh_3)_2]~-(M=Mo,M′=Ag;M=W,M′=Cu,Ag)的付里叶变换红外光谱,并对标题簇阴离子[Cl_2FeS_2WS_2Cu(PPh_3)_2]~-,[Cl_2FeS_2MoS_2Ag(PPh_3)_2]~-和[Cl_2FeS_2WS_2Ag(PPh_3)_2]~-骨架的振动光谱给予经验指认。同时采用"诱导自洽方法计算振动力常数"程序,对簇骨架[Cl_2FeS_2MS_2M~′P_2]进行简正坐标分析。振动频率的计算值与观测值符合良好,两者平均偏差小于1.0%,计算结果支持了振动谱带的归属并表明计算力常数的合理性。文中还讨论了主要价键振动频率的变化规律。  相似文献   

9.
SkeletonVibrationsandForceConstantsof[Fe_2Cr(μ_3-O)(glycine)_6(H_2O)_3](NO_3)_7.3H_2OZhangLin-Na,LinZheng-Yan(StateKeyLaboratoryo...  相似文献   

10.
UNUSUAL FORMATION OF ORGANO-NEODYMIUM AND -SAMARIUM CATIOHS AND X-RAY STRUCTURE OF[(MeOCH_2CH_2C_5H_4)_2Sm(thf)][Co(CO)_4]UNUSUA...  相似文献   

11.
Diantipyrylmethane and tiron spectrophotometric determinations of Ti in the super alloys, Inconel 718 and Inconel 600, have been studied thoroughly. Both reagents formed stable yellow complexes with Ti(IV) in acidic medium. The possible interference from Ni, Fe and Cr was examined. Interference from Fe(III) was eliminated by the reduction of Fe(III) to Fe(II). Cr was removed as chromyl chloride which led to a dramatic improvement in the analytical results for Ti by the tiron photometric method. However, the removal of Cr was not necessary when the diantipyrylmethane method was employed. Consequently, lengthy manipulation of super alloys was required for the tiron determination. These two spectrophotometric methods are compared in terms of simplicity, reproducibility and accuracy.  相似文献   

12.
掺杂纳米TiO2光催化性能的研究   总被引:64,自引:2,他引:64  
利用浸渍法分别制备了Cr、Mn、Fe、Co、Ni、Cu六种过渡金属离子掺杂改性的二氧化钛光催化剂,以乙酸水溶液的光催化氧化反应和二氧化碳还原反应为探针,评价了掺杂催化剂的光催化性能.借助光电子能谱(XPS)、X射线衍射分析(XRD)等手段对掺杂催化剂进行了表征.研究结果表明,经过渡金属离子掺杂后,光催化性能均有不同程度的改善,改善程度按Cr、Co、Ni、Fe、Mn、Cu递增.掺杂后催化剂表面吸附氧的活泼性、金属离子的价态及得电子能力上的差异决定了不同离子掺杂纳米二氧化钛光催化性能的差异.  相似文献   

13.
Ni-Co alloys were electroplated from sulphate electrolyte using addition agents including sodium gluconate,boric acid and cysteine on copper foil by the galvanostatic technique and ultrasound waves.The chemical composition,surface morphologies,crystalline structure and hardness of the Ni-Co alloys were studied using energy dispersive spectroscopy,scanning electron microscope,X-ray diffraction and Vickers testing method,respectively.The effect of current density and addition agents on the microstructure and morphology of Ni-Co alloys were examined.The appropriate concentration of additives and ultrasound waves were found to produce fine and smooth crystals leading to higher hardness of Ni-Co alloys.The microhardness of the Ni-Co alloys was varied between 4860–7530 HV.The surface morphology of coatings was changed from granular to fine due to using of gluconate,boric acid,cysteine and ultrasound waves.The mechanical properties of nanocrystalline Ni-Co alloys showed an increase of the hardness with the growing of Ni content in the alloy.The X-ray diffraction studies indicated that nanocrystalline structure was face-centred cubic for pure Ni and Ni-Co alloys with Co content in the range of 1–75 wt.%.A hexagonal closed-package structure was obtained for pure Co and Ni-Co alloys with the cobalt content with range of 75–99wt.%.  相似文献   

14.
Mechanism of pearlite formation in the base metal in melting of coatings based on self-fluxing alloys was studied. A zone in the form of a complex carboboride (Fe, Ni, Cr, Si) (BC) in the multilayer coating-steel interface was found and studied. The effect of pore space filling by needles of carboboride phases of the solid interlayer was revealed. It was shown that the coating composition and characteristics of strengthening additives (composition and dispersity) affect the structuring of the transition zone.  相似文献   

15.
Equilibrium of Cr atoms between the surface layer and bulk of a binary alloy was analyzed. The Gibbs adsorption equation was used to obtain the dependence of the adsorption activity of atoms in the surface layer on their activity in the bulk. An approximate thermodynamic method was used to calculate the adsorption of Fe (Ni) and Cr atoms in the surface layers of Fe-Cr and Ni-Cr alloys. According to calculations, there was negative adsorption, X Cr ≪ 1, in the surface layer of the alloys caused by a large difference between the Gibbs surface energies of Cr and Fe (or Ni). The negative adsorption of Cr shifted chemical reaction equilibria on the alloy-oxide film boundary both in oxidation in air and in anodic passivation, 3FeO (NiO) + 2Cr = Cr2O3 + 3Fe(Ni), toward oxide film enrichment in the FeO (or NiO) oxide. A unified method for calculating the composition of oxide films on alloys was used for both processes. The method was based on the use of the initial data on the Gibbs surface energy of metals constituting alloys. The calculated oxide film compositions were close to the experimental X-ray photoelectron spectroscopy data.  相似文献   

16.
Surface oxidation of Fe‐19Cr‐17Ni, Fe‐19Cr‐18Ni‐1Al and TiC‐enriched Fe‐19Cr‐18Ni‐1Al alloys was investigated by photoelectron spectroscopy (PES). The experiments were conducted at 323 K in pure O2 (2.7 × 10?6 mbar). Composition and morphology of the nanoscale surface oxides were determined quantitatively by inelastic electron background analysis. Moreover, use of synchrotron radiation facilities were necessary to obtain improved sensitivity for studying minor alloying elements such as Al and Si. The results indicate oxygen‐induced segregation of Al, which significantly hinders the oxidation of the major alloying elements Fe and Cr. Ti remains in its inert carbide form. The relative concentration of Fe within the oxide layer was found to increase with the oxide‐layer thickness, indicating greater mobility of Fe relative to other alloying elements. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

17.
In the present research, a study on the thermodynamical properties of the quinary Co–Cu–Cr–Fe–Ni high-entropy alloys and ternary Ca–Sb–Yb is carried out by the models Kohler, Chou’s general solution method (GSM) and Muggianu. The dependences of composition variation on thermodynamic properties, such as enthalpy of mixing of Co–Cu–Cr–Fe–Ni alloys in simple FCC phase are investigated at the temperatures 1273, 1373, and 1473 K. Moreover, a comparison between the results of the three models and those of other theoretical models shows good mutual agreement.  相似文献   

18.
The electrodeposition of binary Ni–Fe alloys is studied in chloride-based solutions with organic additives. Specific codeposition composition of the electrolyte and operating variables are taken for deposition a wide range of Ni–Fe deposits. Results reveal that in solutions containing sodium citrate and glycolic acid, the nickel content always increases with the current density and nickel concentration. Therefore, nickel reduction rate and the Ni/Fe ratio in the deposits increase. The anomalous codeposition of iron is minimized and the quality of the alloy deposits is improved with the combination of sodium citrate and glycolic acid. Scanning electron micrographs show that, with addition of glycolic acid, the spherical particles become finer and the surface roughness relatively decreases. The XRD patterns of the Ni–Fe deposits exhibit the fcc structure and (111) preferred orientation for alloys with nickel content exceeding 60 wt %. After a heat treatment, additional peaks appear for an Ni–Fe solid solution.  相似文献   

19.
Supportedamorphousalloycatalystshavereceivedmuchattentioninrecentyearsbecausetheyshowlargersurfacearea,higherthermalstabilityandsuperiorcatalyticproperties'-'ascomparedwithultra-fineorrapidlyquenchedmetalmetalloidamorphousalloys.Preparation,characterizationandcatalyticperformanceofsupportedNiBcatalysthavebeenreportedbyseveralresearchgroups,however,onlyonepreparationmethodofsupportedamorphousalloycatalystcontainingNiPwasproposed"'whichwasfoundbyustobeunabletodepositNiPsufficientlyontosupport.…  相似文献   

20.
Graphite-furnace a.a.s, is used for the determination of > 0.0007% Cr, > 0.01% Ni, > 0.007% Fe and > 0.0002% Be in aluminum and its alloys. The samples are dissolved in hydrochloric acid and processed directly after addition of a slight molar excess of diammonium-EDTA over aluminum.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号