Media with engineered magnetization are essential building blocks in superconductivity, magnetism and magnon spintronics. However, the established thin-film and lithographic techniques insufficiently suit the realization of planar components with on-demand-tailored magnetization in the lateral dimension. Here, we demonstrate the engineering of the magnetic properties of CoFe-based nanodisks fabricated by the mask-less technique of focused electron beam induced deposition (FEBID). The material composition in the nanodisks is tuned \emph{in-situ} via the e-beam waiting time in the FEBID process and their post-growth irradiation with Ga ions. The magnetization Ms and exchange stiffness A of the disks are deduced from perpendicular ferromagnetic resonance measurements. The achieved Ms variation in the broad range from 720 emu/cm3 to 1430 emu/cm3 continuously bridges the gap between the Ms values of such widely used magnonic materials as permalloy and CoFeB. The presented approach paves a way towards nanoscale 2D and 3D systems with controllable and space-varied magnetic properties.
@article{arxiv.2012.01481,
title = {Engineered magnetization and exchange stiffness in direct-write Co-Fe nanoelements},
author = {S. A. Bunyaev and B. Budinska and R. Sachser and Q. Wang and K. Levchenko and S. Knauer and A. V. Bondarenko and M. Urbanek and K. Y. Guslienko and A. V. Chumak and M. Huth and G. N. Kakazei and O. V. Dobrovolskiy},
journal= {arXiv preprint arXiv:2012.01481},
year = {2021}
}