TY - JOUR
T1 - Lattice Softening in Metastable bcc CoxMn100 - X (001) Ferromagnetic Layers for a Strain-Free Magnetic Tunnel Junction
AU - Elphick, Kevin
AU - Yoshida, Kenta
AU - Roy, Tufan
AU - Ichinose, Tomohiro
AU - Kunimatsu, Kazuma
AU - Tsuchiya, Tomoki
AU - Suzuki, Kazuya Z.
AU - Tsujikawa, Masahito
AU - Nagai, Yasuyoshi
AU - Mizukami, Shigemi
AU - Shirai, Masafumi
AU - Hirohata, Atsufumi
N1 - Funding Information:
This work was partially supported by Japan Science and Technology Agency (JST) Core Research for Evolutionary Science and Technology (CREST) (Grant No. JPMJCR17J5) and Engineering and Physical Sciences Research Council (EPSRC) (Grant No. EP/V007211/1).
Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/11
Y1 - 2021/11
N2 - In spintronics, one of the long-standing questions is why the MgO-based magnetic tunnel junction (MTJ) is almost the only option for achieving a large tunneling magnetoresistance (TMR) ratio at room temperature, although this is not as large as the theoretical prediction. This study focuses on the development of an almost strain-free MTJ using metastable bcc CoxMn100-x (Co-Mn) ferromagnetic films. We investigate the degree of crystallization in MTJs consisting of Co-Mn/MgO/Co-Mn in relation to their TMR ratios. Cross-section high resolution transmission electron microscopy reveals that almost consistent lattice constants of these layers for 66 ≤ x ≤ 83 with large TMR ratios of 229% at room temperature, confirming the soft nature of the Co-Mn layer with some dislocations at the MgO/Co75Mn25 interfaces. Ab initio calculations confirm the crystalline deformation stability across a broad compositional range in Co-Mn, proving the advantage of a strain-free interface for much larger TMR ratios.
AB - In spintronics, one of the long-standing questions is why the MgO-based magnetic tunnel junction (MTJ) is almost the only option for achieving a large tunneling magnetoresistance (TMR) ratio at room temperature, although this is not as large as the theoretical prediction. This study focuses on the development of an almost strain-free MTJ using metastable bcc CoxMn100-x (Co-Mn) ferromagnetic films. We investigate the degree of crystallization in MTJs consisting of Co-Mn/MgO/Co-Mn in relation to their TMR ratios. Cross-section high resolution transmission electron microscopy reveals that almost consistent lattice constants of these layers for 66 ≤ x ≤ 83 with large TMR ratios of 229% at room temperature, confirming the soft nature of the Co-Mn layer with some dislocations at the MgO/Co75Mn25 interfaces. Ab initio calculations confirm the crystalline deformation stability across a broad compositional range in Co-Mn, proving the advantage of a strain-free interface for much larger TMR ratios.
UR - http://www.scopus.com/inward/record.url?scp=85120534297&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85120534297&partnerID=8YFLogxK
U2 - 10.1103/PhysRevApplied.16.054052
DO - 10.1103/PhysRevApplied.16.054052
M3 - Article
AN - SCOPUS:85120534297
SN - 2331-7019
VL - 16
JO - Physical Review Applied
JF - Physical Review Applied
IS - 5
M1 - 054052
ER -