Tunneling spectra of sputter-deposited CoFeB/MgO/CoFeB magnetic tunnel junctions showing giant tunneling magnetoresistance effect

Autor:	Yusuke Hamada, Koji Tsunekawa, David D. Djayaprawira, Akio Fukushima, Shinji Yuasa, H. Maehara, Hitoshi Kubota, Yoshishige Suzuki, Masaki Mizuguchi, Naoki Watanabe, Taro Nagahama, Rie Matsumoto, Masashi Shiraishi, Yoshinari Kurosaki
Rok vydání:	2005
Předmět:	Tunnel effect Magnetoresistance Condensed matter physics Chemistry Tunnel junction Magnon Materials Chemistry Spin valve Giant magnetoresistance General Chemistry Condensed Matter Physics Quantum tunnelling Amorphous solid
Zdroj:	Solid State Communications. 136:611-615
ISSN:	0038-1098
DOI:	10.1016/j.ssc.2005.08.032
Popis:	We measured differential tunneling conductance (d I /d V , d 2 I /d V 2 ) spectra of spin-valve-type magnetic tunnel junctions (MTJs) with a MgO(001) tunnel barrier layer and amorphous CoFeB ferromagnetic electrodes that show 315% magnetoresistance (MR) ratio at 4.3 K. The d I /d V spectra showed clear reduction in the conductance at around ±400 mV for a parallel magnetic configuration. Such anomalous spectra have never been observed for MTJs with an amorphous Al–O barrier. The d 2 I /d V 2 spectra showed several distinct peaks between 5 and 100 mV. Magnon excitations are assigned to an origin of those peaks and thought to be a dominant process to reduce MR at finite bias voltage.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::3a2fc5e04c142fb1bff328cbdcaf0aa3 https://doi.org/10.1016/j.ssc.2005.08.032 Zobrazit plný text záznamu Full Text from ScienceDirect