Ion beam deposition of Mn-Ir spin valves

MnIr-biased spin valves have been prepared by ion beam deposition. The magn etoresistance (MR) signal reaches 7.7% and the exchange field is 450 Oe wit h a coupling field of 15 Oe and a coercivity of the free layer equal to 4 O e, The (111) texture induced by a very thin Ta buffer layer (thickness < 10 Angstrom) has a strong effect in increasing the MR signal and coupling fie ld, while decreasing the exchange field and coercivity, The blocking temper ature of the MnIr-biased spin valves is 250 degrees C and a thermal stabili ty study shows that the exchange field is constant up to 300 degrees C, und er consecutive 5-h anneals at each temperature. After these anneals, the MR signal is still equal to 5%, These films show better thermal stability tha n equivalent samples prepared by sputtering.