Communications Materials (Jan 2024)

The impact of local pinning sites in magnetic tunnel junctions with non-homogeneous free layers

  • Alex. S. Jenkins,
  • Leandro Martins,
  • Luana C. Benetti,
  • Alejandro Schulman,
  • Pedro Anacleto,
  • Marcel S. Claro,
  • Ihsan Caha,
  • Francis Leonard Deepak,
  • Elvira Paz,
  • Ricardo Ferreira

DOI
https://doi.org/10.1038/s43246-023-00423-x
Journal volume & issue
Vol. 5, no. 1
pp. 1 – 8

Abstract

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Abstract Pinning at local defects is a significant road block for the successful implementation of technological paradigms which rely on the dynamic properties of non-trivial magnetic textures. Here, a comprehensive study of the influence of local pinning sites for non-homogeneous magnetic layers integrated as the free layer of a magnetic tunnel junction is presented, both experimentally and with corresponding micromagnetic simulations. The pinning sites are found to be extremely detrimental to the frequency controllability of the devices, a key requirement for their use as synapses in a frequency multiplexed artificial neural networks. In addition to describing the impact of the local pinning sites in the more conventional NiFe, a vortex-based magnetic tunnel junction with an amorphous free layer is presented which shows significantly improved frequency selectivity, marking a clear direction for the design of future low power devices.