Conductive Atomic Force Microscopy of Small Magnetic Tunnel Junctions with Interface Anisotropy

Stephan K. Piotrowski, Mukund Bapna, Hamid Almasi, Weigang Wang, Larysa Tryputen, Caroline A. Ross, Mingen Li, Chia Ling Chien, Sara A. Majetich

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Magnetization reversal in CoFeB/MgO/CoFeB magnetic tunnel junctions with perpendicular magnetic anisotropy was studied as a function of both diameter (from 87 to 500 nm) and voltage (from-900 to 900 mV) using a conducting atomic force microscope. We found that the tunneling magnetoresistance near zero voltage was \sim 100% for all device sizes. The coercivity of the top CoFeB layer was identical within experimental error for the sizes between 158 and 500 nm but was smaller for 87 nm devices. This suggests a transition from domain-wall-nucleation-driven magnetization reversal to coherent rotation between 87 and 158 nm.

Original languageEnglish (US)
Article number7109902
JournalIEEE Transactions on Magnetics
Volume51
Issue number11
DOIs
StatePublished - Nov 1 2015

Keywords

  • Conductive AFM
  • magnetic tunnel junction
  • perpendicular magnetic anisotropy
  • voltage controlled anisotropy

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

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    Piotrowski, S. K., Bapna, M., Almasi, H., Wang, W., Tryputen, L., Ross, C. A., Li, M., Chien, C. L., & Majetich, S. A. (2015). Conductive Atomic Force Microscopy of Small Magnetic Tunnel Junctions with Interface Anisotropy. IEEE Transactions on Magnetics, 51(11), [7109902]. https://doi.org/10.1109/TMAG.2015.2434798