Magnetic characterization of MnPt/CoFe bilayers using the MOKE technique

• Type: Article in International Scientific Journal
• Date: 2008

Authors

teixeira, j. m. (Author) Other; pereira, a. m. (Author) Other; ventura, j. (Author) REIT; silva, r. f. a. (Author) Other; carpinteiro, f. (Author) Other; araujo, j. p. (Author) FCUP; sousa, j. b. (Author) FCUP; rickart, m. (Author) Other; cardoso, s. (Author) Other; ferreira, r. (Author) Other; freitas, p. p. (Author) Other

Journal

Title: Vacuum

Vol. 82

Pages: 1486-1488

ISSN: 0042-207X

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 3 Citations

Other information

Authenticus ID: P-003-X2P

DOI: 10.1016/j.vacuum.2008.03.072

Abstract (EN): The performance of magnetoresistive devices (spin valves, tunnel junctions), made of two ferromagnetic (FM) layers and separated by a non-magnetic spacer, rely on the existence of two well separated resistance states. For this to occur, one of the FM layer is deposited just adjacent to an antiferromagnetic (AFM) layer. Due to the exchange interaction at the AFM/FM interface, the reversal of the magnetization (M) of such FM-pinned layer occurs at a high applied magnetic field. The magnetization of the other FM layer reverses almost freely when a small magnetic field is applied. Here we study the exchange bias effect in the MnPt (t)/CoFe (50 angstrom) system, using the Magneto-Optical Kerr Effect (MOKE) and domain imaging techniques. The exchange (H-E) and coercive (H-c) fields increase with increasing AFM thickness, saturating for t > 200 angstrom (H-E approximate to 670 Oe and H-c approximate to 315 Oe). Furthermore, we observe that the value of the exchange field is almost independent of the applied magnetic field sweeping rate (up to approximate to 300 kOe/s). Domain imaging allowed us to conclude that magnetization reversal in the studied system proceeds essentially by coherent magnetic moment rotation.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 3