Perpendicular magnetic tunnel junction with W seed and capping layers

H. Almasi, C. L. Sun, X. Li, T. Newhouse-Illige, C. Bi, K. C. Price, S. Nahar, C. Grezes, Q. Hu, P. Khalili Amiri, K. L. Wang, P. M. Voyles, W. G. Wang

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


We present a study on perpendicular magnetic tunnel junctions with W as buffer and capping layers. A tunneling magnetoresistance of 138% and an interfacial magnetic anisotropy of 1.67 erg/cm2 were obtained in optimally annealed samples. However, after extended annealing at 420 °C, junctions with W layers showed extremely small resistance due to interdiffusion of W into the MgO barrier. In contrast, in Ta-based junctions, the MgO barrier remained structurally stable despite disappearance of magnetoresistance after extended annealing due to loss of perpendicular magnetic anisotropy. Compared with conventional tunnel junctions with in-plane magnetic anisotropy, the evolution of tunneling conductance suggests that the relatively low magnetoresistance in perpendicular tunnel junctions is related to the lack of highly polarized Δ1 conducting channel developed in the initial stage of annealing.

Original languageEnglish (US)
Article number153902
JournalJournal of Applied Physics
Issue number15
StatePublished - Apr 21 2017

ASJC Scopus subject areas

  • General Physics and Astronomy


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