@article{cd49cc7b2db04e43a5e793f9ff642bc8,
title = "Observation of boron diffusion in an annealed Ta/CoFeB/MgO magnetic tunnel junction with standing-wave hard x-ray photoemission",
abstract = "The CoFeB/MgO system shows promise as a magnetic tunnel junction with perpendicular magnetization and low critical current densities for spin-torque driven magnetization switching. The distribution of B after annealing is believed to be critical to performance. We have studied the distribution of B in a Ta/Co0.2Fe0.6B0.2/MgO sample annealed at 300°C for 1 h with standing-wave hard x-ray photoemission spectroscopy (SW-HXPS). Comparing experimental rocking curve data to x-ray optical calculations indicates diffusion of 19.5 of the B uniformly into the MgO and of 23.5 into a thin TaB interface layer. SW-HXPS is effective for probing depth distributions in such spintronic structures.",
author = "Greer, {A. A.} and Gray, {A. X.} and S. Kanai and Kaiser, {A. M.} and S. Ueda and Y. Yamashita and C. Bordel and G. Palsson and N. Maejima and Yang, {S. H.} and G. Conti and K. Kobayashi and S. Ikeda and F. Matsukura and H. Ohno and Schneider, {C. M.} and Kortright, {J. B.} and F. Hellman and Fadley, {C. S.}",
note = "Funding Information: A.G., A.X.G., J.B.K., and C.S.F. gratefully acknowledge support from the Director, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, as well as from the scientists of Beamline BL15XU at SPring-8. Two of us (G.P. and A.M.K.) have also been partially supported by an Army Research Office Multi-Disciplinary University Research Grant W911-NF-09-1-0398. The HXPS measurements were performed under the approval of NIMS Beamline Station (Proposal Nos. 2010A4902, 2010B4900, and 2011A4606). The authors are grateful to HiSOR, Hiroshima University and JAEA/SPring-8 for the development of HXPS at BL15XU of SPring-8. This work was partially supported by the Nanotechnology Network Project, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. Work at Tohoku University was supported by the FIRST program of JSPS. Research at Stanford was supported through the Stanford Institute for Materials and Energy Science (SIMES) and the LCLS by the US Department of Energy, Office of Basic Energy Sciences.",
year = "2012",
month = nov,
day = "12",
doi = "10.1063/1.4766351",
language = "English",
volume = "101",
journal = "Applied Physics Letters",
issn = "0003-6951",
publisher = "American Institute of Physics",
number = "20",
}