AVS 66th International Symposium & Exhibition
    Thin Films Division Monday Sessions
       Session TF+EM+MI+MN+OX+PS-MoM

Paper TF+EM+MI+MN+OX+PS-MoM6
Structural and Magnetic Properties of CoPd Alloys for Non-Volatile Memory Applications

Monday, October 21, 2019, 10:00 am, Room A122-123

Session: Functional Thin Films: Ferroelectric, Multiferroics, and Magnetic Materials
Presenter: Sujan Budhathoki, University of Alabama
Authors: S. Gupta, University of Alabama
J.B. Abugri, University of Alabama
B.D. Clark, University of Alabama
P. Komninou, Aristotle University of Thessaloniki
S. Budhathoki, University of Alabama
A.J. Hauser, University of Alabama
P.B. Visscher, University of Alabama
Correspondent: Click to Email
A study of perpendicular magnetic anisotropy (PMA) CoPd alloys is presented as a simple means of pinning MgO-based perpendicular magnetic tunnel junctions (pMTJs) for spin transfer torque magnetic tunnel junction (STT-MRAM) applications. A compositional study of the CoxPd100-x alloys at 50 nm thickness showed that the maximum coercivity and anisotropy was found for Co25Pd75. Perpendicular magnetic tunnel junction stacks were deposited using different compositions of CoPd. Current-in-plane tunneling measurements indicated that the TMR values roughly correlated with the coercivity and anisotropy of the single layers. A thickness study indicated that the alloy was fully perpendicular for thicknesses as low as 20 nm. Various seed layers were employed to optimize the coercivity of the Co25Pd75 layer. Magnetometry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy studies were carried out to relate the magnetic and structural properties of these layers. These studies showed that the highest coercivity Co25Pd75 was achieved on a seed layer of Ta/Pd which helped to crystallize the CoPd layer in an fcc (111) orientation.