Inelastic electron tunneling spectra of MgO-based magnetic tunnel junctions with different electrode designs

被引：35

作者：

Drewello, Volker ^{[1
]}

Schaefers, Markus ^{[1
]}

Schebaum, Oliver ^{[1
]}

Khan, Ayaz Arif ^{[1
]}

Muenchenberger, Jana ^{[1
]}

Schmalhorst, Jan ^{[1
]}

Reiss, Guenter ^{[1
]}

Thomas, Andy ^{[1
]}

机构：

[1] Univ Bielefeld, D-33615 Bielefeld, Germany

来源：

PHYSICAL REVIEW B | 2009年 / 79卷 / 17期

关键词：

electrodes; ferrimagnetic materials; magnesium compounds; magnetic structure; tunnelling magnetoresistance; tunnelling spectra; BIAS CONDUCTANCE-PEAK; MAGNON EXCITATION; SCATTERING;

D O I：

10.1103/PhysRevB.79.174417

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

MgO-based magnetic tunnel junctions with up to 230% tunnel magnetoresistance ratio at room temperature and up to 345% at 13 K are prepared. The lower electrode is either exchange-biased or free, while the top electrode is free or an exchanged-biased artificial ferrimagnet, respectively. Additionally, a pseudo-spin-valve (hard-soft switching) design with two unpinned electrodes is used. Inelastic electron-tunneling spectra for each of these systems show a strong variation in the zero-bias anomaly with a reduced peak for some of the junctions. At voltages around 200 mV additional structures are found, which are not known from junctions with lower magneto resistance, such as alumina-based junctions. We discuss the spectra for the different electrode types and compare our findings with respect to barrier material and magnetoresistance ratio.

引用

页数：6

共 34 条

[1] INELASTIC ELECTRON TUNNELLING SPECTROSCOPY [J].