PUB - Publikationen an der Universität Bielefeld

We report an exchange bias of more than 2700 Oe at room temperature in MnN/CoFe bilayers after high-temperature annealing. We studied the dependence of exchange bias on the annealing temperature for different MnN thicknesses in detail and found that samples with t(MnN) > 32nm show an increase of exchange bias for annealing temperatures higher than T-A = 400 degrees C. Maximum exchange bias values exceeding 2000 Oe with reasonably small coercive fields around 600 Oe are achieved for t(MnN) = 42, 48 nm. The median blocking temperature of those systems is determined to be 180 degrees C after initial annealing at T-A = 525 degrees C. X-ray diffraction measurements and Auger depth profiling show that the large increase of exchange bias after high-temperature annealing is accompanied by strong nitrogen diffusion into the Ta buffer layer of the stacks. (c) 2017 Author(s).