Resonant Tunneling through Electronic Trapping States in Thin MgO Magnetic Junctions

• Type: Article in International Scientific Journal
• Date: 2011

Authors

teixeira, j. m. (Author) FCUP; ventura, j. (Author) FCUP; araujo, j. p. (Author) FCUP; sousa, j. b. (Author) Other; wisniowski, p. (Author) Other; cardoso, s. (Author) Other; freitas, p. p. (Author) Other

Journal

Title: Physical Review Letters

Vol. 106

ISSN: 0031-9007

Publisher: American Physical Society

Indexing

ISI Web of Knowledge - 44 Citations

Scopus - 43 Citations

Other information

Authenticus ID: P-002-RGY

DOI: 10.1103/physrevlett.106.196601

Abstract (EN): We report an inelastic electron tunneling spectroscopy study on MgO magnetic junctions with thin barriers (0.85-1.35 nm). Inelastic electron tunneling spectroscopy reveals resonant electronic trapping within the barrier for voltages V > 0: 15 V. These trapping features are associated with defects in the barrier crystalline structure, as confirmed by high-resolution transmission electron microscopy. Such defects are responsible for resonant tunneling due to energy levels that are formed in the barrier. A model was applied to determine the average location and energy level of the traps, indicating that they are mostly located in the middle of the MgO barrier, in accordance with the high-resolution transmission electron microscopy data and trap-assisted tunneling conductance theory. Evidence of the influence of trapping on the voltage dependence of tunnel magnetoresistance is shown.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 4