Crystallization and magnetic properties in amorphous Co2MnSi alloy films

Wang, Ke; Dong, Shuo; Xu, Zhixin; Huang, Yan

doi:10.1016/j.matlet.2016.05.099

Cited by 10 publications

(1 citation statement)

References 12 publications

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“…The crystallisation degree of the MTJ can be determined by measuring the saturation magnetisation and crystallographic structure [17] [18]. Cross-sectional high resolution transmission electron microscopy (HRTEM) images for MTJ using different annealing conditions have been reported to date [4] [19].…”

Section: Introductionmentioning

confidence: 99%

Lattice Softening in Metastable bcc CoxMn100−x (001) Ferromagnetic Layers for a Strain-Free Magnetic Tunnel Junction

et al. 2021

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In spintronics, one of the long standing questions is why the MgO-based magnetic tunnel junction (MTJ) is almost the only option to achieve a large tunnelling magnetoresistance (TMR) ratio at room temperature (RT) but not as large as the theoretical prediction. This study focuses on the development of an almost strain-free MTJ using metastable bcc CoxMn100-x ferromagnetic films. We have investigated the degree of crystallisation in MTJ consisting of CoxMn100-x/MgO/CoxMn100-x (x = 66, 75, 83 and 86) in relation to their TMR ratios. Cross-sectional high resolution transmission electron microscopy (HRTEM) reveals that almost consistent lattice constants of these layers for 66 ≤ x ≤ 83 with maintaining large TMR ratios of 229% at RT, confirming the soft nature of the CoxMn100-x layer with some dislocations at the MgO/Co75Mn25 interfaces. For x = 86, on the other hand, the TMR ratio is found to be reduced to 142% at RT, which is partially attributed to the increased number of the dislocations at the MgO/Co86Mn14 interfaces and amorphous grains identified in the MgO -2 -barrier. Ab-initio calculations confirm the crystalline deformation stability across a broad compositional range in CoMn, proving the advantage of a strain-free interface for much larger TMR ratios.

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