Probing edge condition of nanoscale CoFeB/MgO magnetic tunnel junctions by spin-wave resonance

M. Shinozaki, T. Dohi, J. Igarashi, Justin Llandro, S. Fukami, Hideo Sato, Hideo Ohno

Research output: Contribution to journalArticlepeer-review

Abstract

We investigate spin-wave resonance in nanoscale CoFeB/MgO magnetic tunnel junctions (MTJs) with a perpendicular easy axis and various free-layer sizes. Two types of MTJs are fabricated by different process conditions, and the spin-wave resonance is measured with homodyne-detected ferromagnetic resonance. We focus on the distance between resonance frequencies of the uniform and spin-wave modes as a function of the free-layer size in order to examine the effect of the edge state of MTJs. A marked difference is observed between the two types of MTJs, and the result is consistently reproduced by a model assuming free-or fixed-edge boundary conditions with or without reduced magnetic properties near the pattern edge for each MTJ. The obtained results indicate that the edge state of nanoscale MTJs is crucially affected by the process condition, and spin-wave resonance can serve as a sensitive probe for the edge condition.

Original languageEnglish
Article number202404
JournalApplied Physics Letters
Volume117
Issue number20
DOIs
Publication statusPublished - 2020 Nov 16

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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