Fabrication of epitaxial heterostructures with halrf-metallic ferromagnets and development of spin-controlled devices

半金属铁磁体外延异质结构的制备和自旋控制器件的开发

基本信息

批准号：
18360143
负责人：
YAMAMOTO Masafumi
金额：
$ 10.66万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

项目摘要

The purpose of the present study was to develop spintronic devices utilizing the half-metallicity of Co-based Heusler alloys (Co_2YZ). Fully epitaxial magnetic tunnel junctions (MTJs) with a Co_2YZ thin film or Co_2YZ thin films and a MgO barrier featuring abrupt and extremely smooth interfaces were fabricated. Furthermore, high tunnel magnetoresistance (TMR) ratios were demonstrated at room temperature (RT) for fabricated Co_2YZ/MgO-based MTJs. The main results are summarized as follows.1) The Heusler alloy-based MTJ device technology was developed. This device technology features the followings: a) all layers in the MTJ trilayer structures are epitaxial and single-crystalline, b) abrupt and atomically flat interfaces between a Co_2YZ (Co_2Cr_<0.6>Fe_<0.4>Al (CCFA), Co_2MnSi (CMS), or Co_2MnGe) thin film and a MgO tunnel barrier, and c) the interface region of CMS thin films underneath a MgO barrier is not oxidized.2) The fabricated CCFA/MgO/Co_<50>Fe_<50> MTJs demonstrated a high TMR ratio of 109 % at RT (317% at 4.2 K).3) Fully epitaxial exchange-biased MTJs with CMS thin films as both lower and upper electrodes and with a MgO barrier were fabricated.The TMR ratios at both RT and 4.2 K increased with increasing the in-situ annealing temperature (T_a) just after the deposition of the upper CMS electrode. Furthermore, a high TMR ratio of 179% at RT (683% at 4.2 K) was demonstrated.In summary, it was demonstrated that epitaxial, single-crystalline heterostructures consisting of Co_2YZ thin films and a MgO barrier are highly promising for spintronic devices that utilize the half-metallicity of Co-based Heusler alloys.

本研究的目的是利用基于CO的Heusler Alloys（CO_2YZ）的半金属性开发自旋设备。制作了带有CO_2YZ薄膜或Co_2yz薄膜的完全外延磁性隧道连接（MTJS），并制造出具有突然和极光滑界面的MGO屏障。此外，在室温（RT）中，基于CO_2YZ/MGO的MTJ在室温（RT）上证明了高隧道磁力（TMR）比。主要结果总结如下。1）开发了基于Heusler合金的MTJ设备技术。 This device technology features the followings: a) all layers in the MTJ trilayer structures are epitaxial and single-crystalline, b) abrupt and atomically flat interfaces between a Co_2YZ (Co_2Cr_<0.6>Fe_<0.4>Al (CCFA), Co_2MnSi (CMS), or Co_2MnGe) thin film and a MgO tunnel barrier, and c) the interface region 2）制造的CCFA/MGO/CO_ <50> Fe_ <50> mtjs的制造的CCFA/MGO/CO_ <50> MTJ显示出RT的高TMR比为109％（4.2 k）的高TMR比为109％（4.2 K）.3）。在上CMS电极沉积之后，RT和4.2 K的比率随着原位退火温度（T_A）的增加而增加。 Furthermore, a high TMR ratio of 179% at RT (683% at 4.2 K) was demonstrated.In summary, it was demonstrated that epitaxial, single-crystalline heterostructures consisting of Co_2YZ thin films and a MgO barrier are highly promising for spintronic devices that utilize the half-metallicity of Co-based Heusler alloys.

项目成果

期刊论文数量（0）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Spin-polarized tunneling in fully epitaxial magnetic tunnel junctions with a full-Heusler alloy thin film [Keynote Talk]

全赫斯勒合金薄膜的全外延磁隧道结中的自旋极化隧道 [主题演讲]

DOI：
发表时间：
2007
期刊：
影响因子：
0
作者：
H. Niwa;K. Matsuda;Y. Akimoto;T. Uemura;and M. Yamamoto;M. Yamamoto
通讯作者：
M. Yamamoto

Tunnel magnetoresistance in fully epitaxial magnetic tunnel junctions with a full-Heusler alloy thin film of Co_2Cr_<0.6>Fe_<0.4>A1 and a MgO tunnel barrier

Co_2Cr_<0.6>Fe_<0.4>A1 全赫斯勒合金薄膜和 MgO 隧道势垒的全外延磁隧道结中的隧道磁阻

DOI：
发表时间：
2007
期刊：
J. Appl. Phys. vol.101
影响因子：
0
作者：
S. Hakamata;T. Ishikawa;T. Marukame;K.-i. Matsuda;T. Uemura;M. Arita;and M. Yamamoto;T. Marukame and M. Yamamoto
通讯作者：
T. Marukame and M. Yamamoto

Nb/強磁性体PdNi/Nbジョセフソン接合の電流‐電圧特性の温度依存性および強磁性膜厚依存性

Nb/铁磁PdNi/Nb约瑟夫森结的电流-电压特性的温度依赖性和铁磁膜厚度依赖性