Influence of the spin Hall angle measurement by shunting effect in Ta/Cu interface

• Main Authors: Liang,Ning-Fang, 梁寧方
• Other Authors: Horng, Lance
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/hp94c8

碩士 === 國立彰化師範大學 === 光電科技研究所 === 106 === In many studies on spin Hall angle of β-Ta, and the value is quite differently. One of the most important factor is the shunting effect. The shunting phenomenon occurs in the transmission of electric current and spin current. The magnitude of the shunt parameter is very close to the order of the spin Hall angle. Thus, the shunting factor is a very important thing to calculate the spin Hall angle. In our study, using the spin Hall material is β-Ta. The structure designed by a piece of copper connect on the β-Ta, and changes electric current and thickness of the copper. The results show that the magnitude of the current independent on the parameter of the shunt effect but the thickness has an effect on the shunt parameters. The thicker thickness is more significant effect to the shunting effect. The 10 nm thickness of the copper shunting effect parameter is larger, and the shunting effect is 58%, which means that Ta/Cu interface has 58% of the current flowing forward, while 42% of the current flows upward into the copper material. It can be seen that the current actually flowing forward is much reduced, which affects the value of spin Hall angle.