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Title: Electric field control of spin re-orientation in perpendicular magnetic tunnel junctions—CoFeB and MgO thickness dependence

Abstract

We report an investigation of electric-field (EF) control of spin re-orientation as functions of the thicknesses of CoFeB free layer (FL) and MgO layer in synthetic-antiferromagnetic pinned magnetic tunnel junctions with perpendicular magnetic anisotropy. It is found that the EF modulates the coercivity (Hc) of the FL almost linearly for all FL thicknesses, while the EF efficiency, i.e., the slope of the linearity, increases as the FL thickness increases. This linear variation in Hc is also observed for larger MgO thicknesses (≥1.5 nm), while the EF efficiency increases only slightly from 370 to 410 Oe nm/V when MgO thickness increases from 1.5 to 1.76 nm. We have further observed the absence of quasi-DC unipolar switching. We discuss its origin and highlight the underlying challenges to implement the EF controlled switching in a practical magnetic memory.

Authors:
; ; ;  [1]
  1. Data Storage Institute, A*STAR (Agency for Science Technology and Research), 5 Engineering Drive 1, DSI Building, Singapore 117608 (Singapore)
Publication Date:
OSTI Identifier:
22311208
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANISOTROPY; ANTIFERROMAGNETISM; BORON COMPOUNDS; COBALT COMPOUNDS; COERCIVE FORCE; CONTROL; EFFICIENCY; ELECTRIC FIELDS; IRON COMPOUNDS; LAYERS; MAGNESIUM OXIDES; MAGNETIC PROPERTIES; MEMORY DEVICES; SPIN ORIENTATION; SUPERCONDUCTING JUNCTIONS; THICKNESS; TUNNEL DIODES; TUNNEL EFFECT

Citation Formats

Meng, Hao, Naik, Vinayak Bharat, Liu, Ruisheng, and Han, Guchang, E-mail: han-guchang@dsi.a-star.edu.sg. Electric field control of spin re-orientation in perpendicular magnetic tunnel junctions—CoFeB and MgO thickness dependence. United States: N. p., 2014. Web. doi:10.1063/1.4891843.
Meng, Hao, Naik, Vinayak Bharat, Liu, Ruisheng, & Han, Guchang, E-mail: han-guchang@dsi.a-star.edu.sg. Electric field control of spin re-orientation in perpendicular magnetic tunnel junctions—CoFeB and MgO thickness dependence. United States. doi:10.1063/1.4891843.
Meng, Hao, Naik, Vinayak Bharat, Liu, Ruisheng, and Han, Guchang, E-mail: han-guchang@dsi.a-star.edu.sg. Mon . "Electric field control of spin re-orientation in perpendicular magnetic tunnel junctions—CoFeB and MgO thickness dependence". United States. doi:10.1063/1.4891843.
@article{osti_22311208,
title = {Electric field control of spin re-orientation in perpendicular magnetic tunnel junctions—CoFeB and MgO thickness dependence},
author = {Meng, Hao and Naik, Vinayak Bharat and Liu, Ruisheng and Han, Guchang, E-mail: han-guchang@dsi.a-star.edu.sg},
abstractNote = {We report an investigation of electric-field (EF) control of spin re-orientation as functions of the thicknesses of CoFeB free layer (FL) and MgO layer in synthetic-antiferromagnetic pinned magnetic tunnel junctions with perpendicular magnetic anisotropy. It is found that the EF modulates the coercivity (Hc) of the FL almost linearly for all FL thicknesses, while the EF efficiency, i.e., the slope of the linearity, increases as the FL thickness increases. This linear variation in Hc is also observed for larger MgO thicknesses (≥1.5 nm), while the EF efficiency increases only slightly from 370 to 410 Oe nm/V when MgO thickness increases from 1.5 to 1.76 nm. We have further observed the absence of quasi-DC unipolar switching. We discuss its origin and highlight the underlying challenges to implement the EF controlled switching in a practical magnetic memory.},
doi = {10.1063/1.4891843},
journal = {Applied Physics Letters},
number = 4,
volume = 105,
place = {United States},
year = {Mon Jul 28 00:00:00 EDT 2014},
month = {Mon Jul 28 00:00:00 EDT 2014}
}