Pt的含量对[Fe/Pt]n多层膜磁性能的影响

采用射频磁控溅射的方法,在玻璃基片上制备了不同膜层结构的[Fe/Pt]n多层膜,经不同温度真空热处理后,得到L10有序结构的FePt薄膜.实验结果表明,[Fe/Pt]n多层膜结构可以有效降低FePt薄膜的有序化温度,350℃退火30min后其平行膜面矫顽力可达1.6×105A/m;多层膜结构中,Pt层厚度与Fe层厚度相同时,矫顽力最大,当Fe、Pt层厚度比偏离1:1时,在Fe/Pt接触处易产生Fe3Pt和FePt3软磁相;Pt层和Fe层厚度相等且总厚度相同的情况下,Fe、Pt单层厚度越薄,有序化温度越低,且对应的矫顽力大.     

Ag衬底层对FePt薄膜结构和性能的影响

采用磁控溅射方法在自然氧化的单晶Si(100)衬底上制备了双层结构的FePt-X/Ag(X=Ag或Pt)薄膜.以20nm厚的Ag做衬底,可以制备出易磁化轴垂直基片的FePt合金薄膜;Ag在FePt薄膜中优先团聚,不利于控制FePt晶粒的长大,调整Pt的含量可以控制热处理过程中FePt薄膜的晶粒尺度;通过XRD、TEM、VSM对薄膜样品的结构、晶粒尺寸的观察和磁性检测,我们认为FePt合金薄膜有序化转变的最佳热处理温度在400℃;经过500℃热处理,薄膜软硬磁耦合较好,晶粒尺寸约为100nm,有最大的矫顽力1.04×106A/m.     

FePtAg-C纳米颗粒薄膜的制备及表征

采用磁控溅射法在硅基片上生长FePt纳米颗粒薄膜。在硅片表面生长MgO籽层用来引发FePt合金薄膜的fct织构,加入C来减小其颗粒尺寸,加入Ag来增强其L10有序度。采用X射线衍射仪（XRD）、超导量子干涉仪（SQUID）和高分辨率透射电镜（TEM）对FePt薄膜进行表征。结果表明制备的薄膜样品具有优良的L10相结构,其M-H曲线表明方形度很好,垂直矫顽力HC有2467 kA/m,颗粒大小为10.4 nm。该薄膜非常适合用做下一代高密度磁存储媒质,可有效提高信息存储密度。     

磁场退火制备FePt/Ag垂直磁化薄膜

采用磁控溅射法在自然氧化的单晶Si（100）基底上制备了（FePL／Ag）10多层薄膜,并在10kA／m磁场中进行了不同温度的真空热处理,研究了磁场作用下,不同热处理温度对FePt薄膜有序化转变及磁性能的影响。X射线衍射研究表明,在磁场作用下通过多层膜设计可以比较容易获得垂直生长的易磁化轴;选择适当的热处理温度、降低多层膜中每层膜厚可以制备出晶粒尺寸细小均匀的FePL／Ag垂直磁化薄膜,适用于高密度垂直磁记录介质材料。     

FePt/B4C垂直磁记录介质薄膜的制备与表征

采用直流及射频磁控溅射结合真空退火的方法成功制备了（001）择优生长的FcPt/B4C多层薄膜并对其结构与磁性能做了初步的表征．结果表明，在每一个FbPt单元层中能得到较好（001）面择优的fet相FbPt合金，并且随着B4C含量的增大，薄膜的有序度提高．高分辨透射电子显微镜及其傅立叶变换表明，FePt层为具有（001）织构的fct相Fe55Pt45合金．样品的M-H曲线显示其垂直膜面方向矫顽力约为302.481kA/m；平行膜面方向矫顽力很小．     

不同厚度分层沉积对多层NiFeCo/Ag薄膜GMR效应的影响

用射频磁控溅射法制备了调制周期分别为5 nm、10 nm、15 nm、20 nm的NiFeCo/Ag非连续多层膜.用俄歇能谱仪测量薄膜的成分,用原子力显微镜观测NiFeCo膜层及Ag膜层的表面形貌,用四探针法测量了溅射态的及在280℃、360℃、400℃退火后的多层膜的GMR值.结果表明:薄膜厚度越大,NiFeCo膜层及Ag膜层的表面粗糙度越大.在经各种不同温度退火后,具有[NiFeCo(10nm)/Ag(10nm)]×20结构的多层膜的GMR效应均比其它结构的多层膜的GMR效应强.退火温度也会影响多层膜的GMR值.经360℃退火后,在79.6 kA/m的外加饱和场下[NiFeCo(10nm)/Ag(10nm)]×20呈现出最强的巨磁电阻效应,其GMR值达到11%.     

添加AlN对FePt薄膜结构和磁性的影响

采用射频磁控溅射制备了FePt(50nm)和[FePt(2,3,5nm)/AlN(1nm)]n膜,之后在550℃退火30min,研究了周期数(n)和AlN含量对[FePt/AlN]_n系列多层膜结构及磁性的影响.结果表明,多层膜的矫顽力和矩形比均在n=8时出现较大值;周期数的增大会引起晶粒尺寸的长大;AlN的加入不但可以抑制FePt粒子的长大,使晶粒体积(V_grain)和磁激活体积(V*)趋于一致,而且还能有效地降低晶粒间交换耦合作用,并且AlN含量越大,晶粒间交换耦合作用的程度越弱.     

Cu覆盖层对CoCrPt颗粒膜的微结构和磁特性的影响

在室温下,应用对靶磁控溅射设备制备了系列Cu(x nm)/CoCrPt(40nm)/Cu(20nm)三明治结构的纳米颗粒膜,随后进行了原位退火.实验发现Cu覆盖层的厚度(x)对颗粒膜的微结构和磁特性有很大影响.样品垂直方向的矫顽力在x=11nm时达到最大,为138kA/m,平行于膜面方向的矫顽力基本上与x的变化无关,且所有的样品都显示出很强的垂直各向异性.退火后的CoCrPt薄膜呈六角密堆积(HCP)结构,AFM和MFM测量显示在x=11nm时,颗粒的平均粒径和磁畴尺寸均为最小.开关场分布(SFD)的测量表明,退火有效地减弱了颗粒间的交换耦合作用.     

Effects of Ag Layer on the Structure and Magnetic Properties of FePt:AlN Composite Films

[AlN/FePt] 10 , [AlN/FePt] 10 /Ag and Ag/[AlN/FePt] 10 thin films were deposited by magnetron sputtering onto 7059 glass substrates, then were annealed at 550 °C for 30 min. It is found that introducing non-magnetic Ag underlayer can improve the ordering and (001) preferred orientation of FePt grains. Furthermore, the (001) texture of FePt grains increases with increasing Ag underlayer thickness. However, with Ag top layer given, it can only be observed that the ordering of FePt grains was promoted.     

CoCrPtNb/CrTi/C玻璃盘基磁记录介质制备与性能

采用CoCrPtNb四元合金作磁记录介质,并使用多层膜结构C/(CoCrPt)100-xNbx/CrTi/C/Glass Substrate制备硬盘磁记录介质.实验结果表明此种薄膜记录介质,即使在室温下溅射,也可得到高达240kA/m的矫顽力;此类薄膜在550℃高温下,经过30min退火后,其矫顽力有较大幅度提高,并在Nb含量为2.4%(原子分数)时达到极大值360kA/m此时剩磁比S=0.90,矫顽力矩形比S*=0.92,从而制成了适于高密度或超高密度磁记录使用的薄膜介质.并详细分析了在室温条件下溅射,此种介质矫顽力与Nb含量变化的关系;并对退火后介质矫顽力与Nb含量变化的关系也进行了讨论.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.