基片对交替溅射制备的MnZn铁氧体薄膜结构和磁性的影响

使用成分分别为MnFe₂O₄和ZnFe₂O₄的靶,使用射频溅射交替沉积制备了成分不同的Mn_1-xZn_xFe₂O₄薄膜,沉积薄膜所用基片分别为单晶硅Si（100）,氧化的单晶硅SiO₂/Si（100）, ZnFe₂O₄为衬底的单晶硅ZnFe< 关键词： MnZn铁氧体 纳米晶 软磁性 磁性薄膜     

Reduction of Ordering Temperature of FePt-Al2O3 Thin Films by N2 Addition During Sputtering

We investigate the effect of N2 addition during sputtering on the microstructure and magnetic properties of FePt-Al2O3 thin films. The texture of FePt phase in FePt-Al2O3 thin films changes from （111） to a more random orientation by N2 addition during sputtering. The ordering temperature of FePt phase reduces about 100℃ with appropriate N2 partial pressure. A larger coercivity of 6.0 × 10^5 Aim is obtained with N2 partial pressure about 15%. Structural analysis reveals that a small quantity of Fe3N phase forms during sputtering and the release of N atoms during the post annealing induces a large number of vacancies in the films, which benefits to the transformation of FePt phase from fcc to fct.     

磁斯格明子器件及其应用进展

磁斯格明子是一种具有准粒子特性的拓扑纳米磁畴壁结构.由于磁斯格明子具有较好的稳定性和新奇的动力学特性,并可被磁场、电场、电流等方式调控,有望成为高密度、低耗能、非易失性信息存储及逻辑运算的新兴信息载体.自2009年磁斯格明子首次被实验观测到至今,已有多种基于磁斯格明子的器件概念和原型器件被提出.本文对基于磁斯格明子应用的研究进展进行综述,对现阶段几种具有代表性的磁斯格明子器件应用进行简要介绍、分析和总结,包括基于磁斯格明子的赛道存储器件、逻辑计算器件、类晶体管功能器件和纳米级微波振荡器;同时阐述了几种可能的通过磁斯格明子表达二进制信息元的方法;并展望了磁斯格明子的其他潜在应用以及未来基于磁斯格明子器件应用的发展方向.     

Skyrmion-based logic gates controlled by electric currents in synthetic antiferromagnet

Skyrmions in synthetic antiferromagnetic (SAF) systems have attracted much attention in recent years due to their superior stability, high-speed mobility, and completely compensated skyrmion Hall effect. They are promising building blocks for the next generation of magnetic storage and computing devices with ultra-low energy and ultra-high density. Here, we theoretically investigate the motion of a skyrmion in an SAF bilayer racetrack and find the velocity of a skyrmion can be controlled jointly by the edge effect and the driving force induced by the spin current. Furthermore, we propose a logic gate that can realize different logic functions of logic AND, OR, NOT, NAND, NOR, and XOR gates. Several effects including the spin-orbit torque, the skyrmion Hall effect, skyrmion-skyrmion repulsion, and skyrmion-edge interaction are considered in this design. Our work may provide a way to utilize the SAF skyrmion as a versatile information carrier for future energy-efficient logic gates.     

交替溅射法制备BaM铁氧体薄膜的特性研究

以双靶射频溅射和交替沉积的方法制备了不同化学组成的BaM铁氧体薄膜.对所沉积的薄膜进行了两种不同方式的热处理.通过热处理后铁氧体薄膜的X射线衍射(XRD), 逆转换电子穆斯堡尔谱(CEMS)及原子力显微镜(AFM)等微观结构的分析和宏观磁性的测试,结果表明两步骤退火过程对于垂直取向结构的形成是有利的.     

高密度磁记录用La-Zn替代锶铁氧体薄膜

用射频溅射装置制备了La-Zn替代磁铅石型锶铁氧体(SrM)薄膜(La_xSr_1-xZn_xFe_12-xO₁₉,0≤x≤0.4),通过对样品微结构及磁性的研究,发现替代可以有效控制薄膜中晶粒的生长,合适的替代量(x=0.4)可得到平均尺寸大约为12nm的六角片状晶粒.饱和磁化强度M_s随替代量x的增加出现极大值,而矫顽力H_c则呈上升趋势.同时替代使薄膜室温下的 关键词： 铁氧体薄膜 磁记录     

Studies on high-moment soft magnetic FeCo/Co thin films

The dependences of soft magnetic properties and microstructures of the sputtered FeCo (=FeFeCo薄膜 溅射条件 软磁性 高饱和磁化强度FeCo film, sputtering conditions, high saturation magnetization, soft magnetic properties2005-10-263/7/2006 12:00:00 AMThe dependences of soft magnetic properties and microstructures of the sputtered FeCo （=Fe65Co35） films on Co underlayer thickness tCo, FeCo thickness tFeCo, substrate temperature Ts and taxget-substrate spacing dT-s are studied. FeCo single layer generally shows a high coercivity with no obvious magnetic anisotropy. Excellent soft magnetic properties with saturation magnetization μ0Ms of 2.35 T and hard axis coercivity Hch of 0.25 kA/m in FeCo films can be achieved by introducing a Co underlayer. It is shown that sandwiching a Co underlayer causes a change in orientation and reduction in grain size from 70 nm to about 10 nm in the FeCo layer. The magnetic softness can be explained by the Hoffmann＇s ripple theory due to the effect of grain size. The magnetic anisotropy can be controlled by changing dT-S, and a maximum of 14.3 kA/m for anisotropic field Hk is obtained with dT-S=18.0 cm.