基于氧化镁的垂直磁隧道结自旋阀在顶部和底部Co2Fe6B2自由层结构之间的隧穿磁电阻比比较

Tunneling-Magnetoresistance Ratio Comparison of MgO-Based Perpendicular-Magnetic-Tunneling-Junction Spin Valve Between Top and Bottom Co2Fe6B2 Free Layer Structure.

作者信息

Lee Du-Yeong, Lee Seung-Eun, Shim Tae-Hun, Park Jea-Gun

机构信息

Department of Electronics and Computer Engineering, Hanyang University, Seoul, 04763, Republic of Korea.

出版信息

Nanoscale Res Lett. 2016 Dec;11(1):433. doi: 10.1186/s11671-016-1637-9. Epub 2016 Sep 27.

DOI:10.1186/s11671-016-1637-9

PMID:27677304

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5039147/

Abstract

For the perpendicular-magnetic-tunneling-junction (p-MTJ) spin valve with a nanoscale-thick bottom Co2Fe6B2 free layer ex situ annealed at 400 °C, which has been used as a common p-MTJ structure, the Pt atoms of the Pt buffer layer diffused into the MgO tunneling barrier. This transformed the MgO tunneling barrier from a body-centered cubic (b.c.c) crystallized layer into a mixture of b.c.c, face-centered cubic, and amorphous layers and rapidly decreased the tunneling-magnetoresistance (TMR) ratio. The p-MTJ spin valve with a nanoscale-thick top Co2Fe6B2 free layer could prevent the Pt atoms diffusing into the MgO tunneling barrier during ex situ annealing at 400 °C because of non-necessity of a Pt buffer layer, demonstrating the TMR ratio of ~143 %.

摘要

对于具有纳米级厚度底部Co2Fe6B2自由层且在400°C下进行非原位退火的垂直磁隧道结（p-MTJ）自旋阀（其已被用作常见的p-MTJ结构），Pt缓冲层的Pt原子扩散到MgO隧道势垒中。这将MgO隧道势垒从体心立方（b.c.c）结晶层转变为b.c.c、面心立方和非晶层的混合物，并迅速降低了隧道磁电阻（TMR）比率。具有纳米级厚度顶部Co2Fe6B2自由层的p-MTJ自旋阀由于不需要Pt缓冲层，可在400°C非原位退火期间防止Pt原子扩散到MgO隧道势垒中，其TMR比率约为143%。