CONTROL OF SPIN CONFIGURATION OF MAGNETIC ULTRA-THIN FILMS

磁性超薄膜自旋构型的控制

基本信息

批准号：
08405024
负责人：
TSUNASHIMA Shigeru
金额：
$ 25.79万
依托单位：
NAGOYA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08405024/
关键词：
SPIN-DEPENDENT ELECTRONIC TRANSPORT MAGNETO-OPTICAL EFFECT ANTI-FERRO MAGNETISM SPIN VALVE BLOCKING TEMPERATURE KERR ROTATION MAGNETIC ULTRA-THIN FILMS MAGNETIC FORCE SCANNING MICROSCOPE

项目摘要

Giant magnetoresistance (GMR) effect has been found in a wide variety of materials. Concerning amorphous materials, however, very little has been reported so far. Since amorphous magnetic films have usually excellent soft magnetic properties, such as low coercivity, high permeability and relatively high resistivity, they have been often applied for inductive readout heads. For the GMR, we found that spin valves using amorphous CoFeB exhibit relatively large MR ratios of 4 to 6%. These values are comparable to or even larger than those of crystalline NiFe spin valves. NiO/CoFeB/Cu/CoFeB spin valves with B content of 0 to 10 atm.% were prepared to investigate the dependence of the giant magnetoresistance effect on the thickness of free magnetic layers. In the spin valves, giant magnetoresistance effects were observed even when the free magnetic layers were very thin down to 1 or 0.5 mm. For lower B content, the MR ratio rapidly increased with the increase of the thickness of free magnetic layers, while for higher B content, the MR ratio exhibited the maximum at the thickness which is roughly equal to the mean free path of electrons in the magnetic layers. By using Camley - Barnas model, the value of the MR ratio and the resistivity can be consistently explained if the specular reflection of electrons is considered at the interface between magnetic and nonmagnetic layers.

巨磁阻（GMR）效应已在多种材料中被发现。然而，迄今为止，关于非晶材料的报道还很少。由于非晶磁性薄膜通常具有优异的软磁性能，例如低矫顽力、高磁导率和相对高的电阻率，因此它们经常应用于感应读出头。对于 GMR，我们发现使用非晶 CoFeB 的自旋阀表现出相对较大的 MR 比率，为 4% 至 6%。这些值与晶体 NiFe 自旋阀的值相当甚至更大。制备了B含量为0至10 atm.%的NiO/CoFeB/Cu/CoFeB自旋阀，以研究巨磁阻效应对自由磁层厚度的依赖性。在自旋阀中，即使自由磁性层非常薄至 1 或 0.5 毫米，也可以观察到巨磁阻效应。对于较低 B 含量，MR 比随着自由磁层厚度的增加而迅速增加，而对于较高 B 含量，MR 比在大致等于磁层中电子平均自由程的厚度处表现出最大值。层。通过使用Camley-Barnas模型，如果在磁性层和非磁性层之间的界面处考虑电子的镜面反射，则可以一致地解释MR比和电阻率的值。