System Maintenance:
There may be intermittent impact on performance while updates are in progress. We apologize for the inconvenience.
By Topic

MgO-Based Double Barrier Magnetic Tunnel Junctions With Synthetic Antiferromagnetic Free Layer

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

6 Author(s)
Dalai Li ; Beijing Nat. Lab. of Condensed Matter Phys., Inst. of Phys., Beijing, China ; Jiafeng Feng ; Guoqiang Yu ; Hongxiang Wei
more authors

CoFeB/Ru/CoFeB has been used as the middle free layer in MgO-based double barrier magnetic tunnel junctions (DBMTJs). The tunneling magnetoresistance (TMR) ratio, V1/2 (bias voltage at half maximum TMR ratio) and Vout (output voltage, defined as V multiplied by TMR ratio) have been investigated as a function of annealing temperature (Ta) and Ru thickness (tRu) in the free layer. Magnetization data reveal that the two CoFeB layers in CoFeB/Ru/CoFeB are antiferromagnetically coupled. Compared with V1/2 of only 0.31 V for single barrier MTJs (SBMTJs) annealed at 375°C, V1/2 for DBMTJs is up to 0.66 V. By increasing Ta, TMR ratio first increases, reaching the highest critical value, and then decreases. The highest TMR ratio is 181% with tRu= 0.6 nm, which is much higher than that obtained in the DBMTJs with the pure CoFeB as the free layer. The improved TMR ratio is mainly due to the relatively thorough crystallization of the CoFeB layers in the free layer. The thermal annealing has been proven to be an effective method to remove the dissimilarity of the top and bottom CoFeB/MgO interfaces. Vout in the positive and negative voltage branches follows the same trend as that of TMR ratio with Ta.

Published in:

Magnetics, IEEE Transactions on  (Volume:49 ,  Issue: 10 )