Study on spin-valve type multi-value memory using spin glass/ferromagnetic exchange coupled thin film

Magnetic anisotropy and the magnetic phase transition temperature in reentrant spin glass NiMn/Cu multilayer and NiMn/Cu/Ni trilayer films were investigated to fabricate a spin valve type memory.对于三层薄膜来说，场相关的磁抵抗力已被测量，以讨论巨型磁抵抗力（GMR）效应的可能贡献。NiMn/Cu multilayer和NiMn/Cu/Ni trilayer薄膜准备好使用在超高真空室中的氩束散射方法。使用superconducting quantum interference device （SQUID）magnetic anisotropy被估计。在NiMn/Cu multilayer sample中使用dreasing the film thickness的磁性相位转换温度。当样本被退火时，铁磁相位转换温度升高时。这一索引表明，对被忽视的NiMn样品的铁磁磁性化已被保留为与该非被忽视的样品相比较的较高温度。在添加中，磁异源场被分析为三聚体样本中的铜层厚度的一个函数。As a result， we found that a magnetic coupling between NiMn and Ni layers becomes pronounced when the thickness of Cu layer is thinner than a thickness between 30 and 59 A D4 D4。这是一个重要的信息，可以在任何需要的磁层之间进行解码的GMR三层电影中制作。GMR效应可能并不被认为是因为异向磁电阻的贡献在三层样本中具有重要意义，因此三层之间电阻的微小差异。

Magnetic anisotropy and the magnetic phase transition temperature in reentrant spin glass NiMn/Cu multilayer and NiMn/Cu/Ni trilayer films were investigated to fabricate a spin valve type memory. For the trilayer film, the field dependent magneto-resistance was measured to discuss the possible contribution from the giant magneto-resistance (GMR) effect.NiMn/Cu multilayer and NiMn/Cu/Ni trilayer film were prepared using the Ar ion-beam sputtering method in an ultra high vacuum chamber. The magnetic anisotropy was estimated using a superconducting quantum interference device (SQUID) magnetometer.The magnetic phase transition temperatures decrease with decreasing the film thickness in NiMn/Cu multilayer sample. When the sample was annealed, however, the ferromagnetic phase transition temperature increased. This indicates that the ferromagnetic magnetization of the annealed NiMn sample is maintained up to a higher temperature compared with the non-annealed sample. In addition, the magnetic anisotropy field was analyzed as a function of the thickness of the Cu layer in the trilayer sample. As a result, we found that a magnetic coupling between NiMn and Ni layers becomes pronounced when the thickness of Cu layer is thinner than a thickness between 30 and 59 AィイD4゜ィエD4. This is an important information to fabricate the GMR trilayer film in which the decoupling between the magnetic layers is required. The GMR effect could not be confined because the contribution from the anisotropic magneto resistance is significant in the trilayer sample, due to the small difference of the resistance among the three layers.