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1.
双层耦合膜的磁光克尔效应研究   总被引:2,自引:0,他引:2  
刘兴阶  许忠 《功能材料》1993,24(1):64-66
稀土-过渡族金属(RE-TM)非晶垂直磁化膜用于磁光记录材料已被广泛研究。为了提高材料的读出性能,提高分辨率,降低误码率,希望材料有较大的磁光克尔旋转角θ_k。本文采用磁光双层膜耦合结构,将信息的记录和读出分别由记录层(Storage Layer)薄膜和读出层(Readout Layer)薄膜完成,将磁光克尔旋转角θ_k由单层膜的小于0.30°,提高到双层膜的0.38°,较好地解决了这一问题。  相似文献   

2.
由费尔德常数大的石榴石磁光薄膜制成的磁光调制器具有体积小,驱动功率低等优点,将它应用于椭偏测量中,可以降低对激光器输出光强稳定性的要求,测量准确度也会得到较大的提高。  相似文献   

3.
使用射频磁控溅射法在非晶态的二氧化硅衬底上制备Ce1YIG磁光薄膜。生成的Ce1YIG薄膜为非晶态形式 ,经过后续的热处理过程 ,转变为晶化薄膜 ,在用波长为 6 30nm的激光测量时 ,薄膜的饱和法拉弟旋转系数θF 为 80 0°/mm。晶化薄膜具有很强的平行于膜面的磁化强度 ,用VSM测得晶化薄膜的居里温度为 2 2 0℃。实验结果表明 :所制备的薄膜适宜于制备波导型磁光隔离器。同时 ,这一方法为进一步研究非互易平面光波回路打下了基础  相似文献   

4.
稀土铁石榴石薄膜被认为是最具应用前景的下一代磁光记录材料。稀土铁石榴石薄膜具有高的矫顽力、良好的热、化学稳定性及强的磁光效应等特点;特别是当Bi3+和Ce3+离子部分取代石榴石结构中的稀土离子后,可以极大地增强其磁光效应。本文就磁光记录的原理、磁光存储材料、稀土铁石榴石磁光薄膜的制备及其如何降低石榴石薄膜中的晶界噪声等问题作了一些探讨。  相似文献   

5.
黄强  冯则坤 《材料导报》1997,11(5):35-37
对新型掺钇石榴石磁光薄膜材料的制备工艺、磁光特性及理论分析进行了较全面的评述,并指出今后研究的方向。  相似文献   

6.
本文讨论了稀土-过渡金属(以下简写为 RE-TM)非晶合金膜用作磁光记录介质的理论和 TbFeCo 膜的特性。采用射频溅射技术制备出 TbFeCo 非晶垂直磁化膜。膜的垂直各向异性常数K_u 为2.94×10~(5J)/m~3,克尔旋转角θ_k 为0.24-0.29°。得到了θ_k 随过渡金属 Co 含量而变化的曲线。当 Co 在 TM 次网络中含量达50%时,θ_k 有最大值0.29°。在膜被复盖一层 SiO_2或 AlN 之后,θ_k 从0.29°提高到0.55°或1.48°。(TbFeCo+AlN)膜的θ_k 达到1.48°这样高的值,尚未见文献报导。这种膜可以直接用作磁光记录介质。  相似文献   

7.
采用射频磁控溅射方法制备了SmDyFeCo非晶磁光薄膜,研究了氩气压,溅射功率对SmDyFeCo薄膜磁特性的影响。实验表明,和DyFeCo非晶薄膜相比,SmDyFeCo非晶薄膜的矫顽力Hc随温度变化更为缓慢,并且具有更大的垂直磁各向异性常数,因而具有更好的记录特性,本征磁光克尔角可达0.31,可以作为一种实用化的磁光记录介质。  相似文献   

8.
本文综述了稀土铁石榴石磁光材料及磁光器件研究的最新进展;对最具应用价值的高掺Bi系列和掺Ce系列石榴石磁光材料作了介绍,在磁光器件方面选择了最具代表性的磁光隔离器和光纤电渗/磁场测试仪加以讨论。  相似文献   

9.
本文综述了稀土铁石榴石磁光材料及磁光器件研究的最新进展;对最具应用价值的高掺Bi系列和掺Ce系列石榴石磁光材料作了介绍;在磁光器件方面选择了最具代表性的磁光隔离器和光纤电流/磁场测试仪加以讨论  相似文献   

10.
采用射频磁控溅射法在玻璃基片上制备了TbFeCo/Ag非晶垂直磁化膜,研究了Ag底层厚度对TbFeCo薄膜磁性能的影响。原子力显微镜、振动样品磁强计与磁光盘测试仪测量结果表明:薄的银底层具有较高的表面粗糙度可以显著增大TbFeCo薄膜的矫顽力,改善TbFeCo薄膜的磁光温度特性,该薄膜有望用作高密度垂直记录介质与光磁混合记录介质。  相似文献   

11.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

12.
Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.  相似文献   

13.
In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.  相似文献   

14.
Quality Study of Honeycomb Core Shaping Without Wax Stabilization   总被引:1,自引:0,他引:1  
Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.  相似文献   

15.
The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……  相似文献   

16.
Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.  相似文献   

17.
We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.  相似文献   

18.
Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.  相似文献   

19.
ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.  相似文献   

20.
Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.  相似文献   

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