Ultra-High Density Magnetic Memory Cells

我们已经研究了亚微米磁性存储器单元的磁性和磁化过程，以便找到增加MRAM（磁性随机存取存储器）密度的突破。(1)研究了磁存储器的记录方法。具有部分平面外侧的非对称环点（材料：5-20 nm厚的Ni-20at%Fe，直径：500-1000 nm）的磁化方向由面内磁场控制在顺时针和逆时针之间，即使普通环点需要由垂直电流引起的顺时针和逆时针磁场。(2)我们还发现，杯形磁存储单元需要较低的磁场比环形存储器记录。(3)Ni-Fe（10 nm）/Mn-Ir（10 nm）环点具有固定的磁化方向。(4)记录在磁存储器中的信息可以使用具有导电探针的原子力显微镜来检测。

We have investigated magnetic properties and magnetization processes of sub-micron magnetic memory cells in order to find a breakthrough that increases a density of MRAM (magnetic random access memory).(1) We have investigated method for recording magnetic memory. The magnetization direction of the asymmetric ring dots (material: 5-20 nm thick Ni-20at%Fe, diameter: 500-1000 nm) that have partly planed outer sides were controlled between clockwise and counterclockwise by in-plane magnetic fields, even though the ordinary ring dots needed the clockwise and counterclockwise magnetic fields caused by the perpendicular current.(2) We also have found that the cup-shaped magnetic memory cell required lower magnetic field to be recorded than the ring memory.(3) The Ni-Fe(10 nm)/Mn-Ir(10 nm) ring dot has fixed magnetization direction.(4) The information recorded in the magnetic memory can be detected using atomic force microscopy with conductive probe.