Title :
Ion beam deposition of Mn-Ir spin valves
Author :
Gehanno, Véronique ; Freitas, Paula P. ; Veloso, Anabela ; Ferrira, J. ; Almeida, Bernard0 ; Soasa, J.B. ; Kling, A. ; Soares, J.C. ; da Silva, M.F.
Author_Institution :
INESC, Lisbon, Portugal
fDate :
9/1/1999 12:00:00 AM
Abstract :
Half-biased spin valves have been prepared by ion beam deposition. The magnetoresistance (MR) signal reaches 7.7% and the exchange field is 350 Oe with a coupling field of 15 Oe and a coercivity of the free layer equal to 4 Oe. The (111) texture induced by a very thin Ta buffer layer (thickness <10 Å) has a strong effect in increasing the MR signal and coupling field, while decreasing the exchange field and coercivity. The blocking temperature of the MnIr-biased spin valves is 250°C and a thermal stability study shows that the exchange field is constant up to 300°C, under consecutive 5-h anneals at each temperature. After these anneals, the MR signal is still equal to 5%. These films show better thermal stability than equivalent samples prepared by sputtering
Keywords :
annealing; coercive force; exchange interactions (electron); ferromagnetic materials; giant magnetoresistance; ion beam assisted deposition; iridium alloys; magnetic multilayers; manganese alloys; spin valves; tantalum; thermal stability; (111) texture; 10 A; 250 C; 300 C; 5 h; MR signal; Mn-Ir spin valves; MnIr-Ta; MnIr-biased spin valves; blocking temperature; coercivity; coupling field; exchange field; half-biased spin valves; ion beam deposition; magnetoresistance signal; thermal stability; thin Ta buffer layer; Annealing; Buffer layers; Coercive force; Couplings; Ion beams; Magnetoresistance; Spin valves; Sputtering; Temperature; Thermal stability;
Journal_Title :
Magnetics, IEEE Transactions on
