Seminar: Growth of functional materials (metallic, superconducting, and magnetic) by means of focused electron and ion irradiation

The technologies that use focused electron and ion beams are very powerful for modeling materials at the nanoscale [1]. Here, I will talk about the processes that, based on these techniques, have been developed in our group to obtain metallic, magnetic and superconducting materials. In particular, the growth induced by a focused ion beam in combination with a precursor gas (FIBID) is a relevant technique to directly obtain metallic and superconducting materials [2, 3]. The FIBID technique is generally slow compared to other nanolithography technologies, which limits its range of applications. I will introduce two strategies to improve the growth rate using a focused ion beam. Firstly, the use of FIBID in cryogenic conditions (Cryo-FIBID) will be introduced, based on the formation of a condensed layer of the precursor material by cooling the substrate. Using a cryogenic module based on liquid nitrogen, we have applied Cryo-FIBID to obtain deposits of W [4], Pt [5] and Co [6], observing improvements of up to three orders of magnitude in the growth rate in comparison with the FIBID process at room temperature. The second strategy is based on the use of organometallic films of palladium acetate, which can be transformed into metallic Pd films through a low dose of focused ion irradiation [7]. On the other hand, the growth induced by a focused electron beam in combination with a precursor gas (FEBID) has proven to be of great interest for growing magnetic materials. In the talk I will show the application of this technique to magnetically functionalize cantilevers and investigate the magnetic properties at the nanoscale through magnetic force microscopy [8, 9].

[1] Nanofabrication, Editor J. M. De Teresa, Institute of Physics (IOP), Bristol (U.K.), 2020 and K. Höflich et al., “Roadmap for focused ion beam technologies”, Applied Physics Reviews, vol. 10, p. 041311, 2023.

[2] P. Orús, F. Sigloch, S. Sangiao, J. M. De Teresa, “Superconducting materials and devices grown by focused ion and electron beam induced deposition”, Nanomaterials, vol. 12, p. 1367, 2022.

[3] F. Sigloch, S. Sangiao, P. Orús, J. M. De Teresa, “Large output voltage to magnetic flux change in nanoSQUIDs based on direct-write Focused Ion Beam Induced Deposition technique”, Nanoscale Advances, vol. 4, p. 4628, 2022.

[4] R. Córdoba, P. Orús, S. Strohauer, T. E. Torres, J. M. De Teresa, “Ultra-fast direct growth of metallic micro- and nano-structures by focused ion beam irradiation”, Scientific Reports, vol. 9, p. 14076, 2019.

[5] A. Salvador-Porroche, S. Sangiao, P. Philipp, P. Cea, J. M. De Teresa, “Optimization of Pt-C deposits by Cryo-FIBID: substantial growth rate increase and quasi-metallic behaviour”, Nanomaterials, vol. 10, p. 1906, 2020.

[6] A. Salvador-Porroche, S. Sangiao, C. Magén, M. Barrado, P. Philipp, D. Belotcerkovtceva, M. V. Kamalakar, P. Cea, J. M De Teresa, “Highly-efficient growth of cobalt nanostructures using focused ion beam induced deposition under cryogenic conditions: application to electrical contacts on graphene, magnetism and hard masking”, Nanoscale Advances, vol. 3, p. 5656, 2021.

[7] A. Salvador-Porroche, L. Herrer, S. Sangiao, P. Philipp, P. Cea, J. M. De Teresa, “High-throughput direct writing of metallic micro- and nano-structures by focused Ga+ beam irradiation of palladium acetate films”, ACS Applied Materials and Interfaces, vol. 14, p. 28211, 2022.

[8] M. Jaafar, J. Pablo-Navarro, E. Berganza, P. Ares, C. Magén, A. Masseboeuf, C. Gatel, E. Snoeck, J. Gómez-Herrero, J. M. De Teresa, A. Asenjo, “Customized MFM probes based on magnetic nanorods”, Nanoscale, vol. 12, p. 10090, 2020.

[9] H. Mattiat et al., “Nanowire magnetic force sensors fabricated by focused electron beam induced deposition”, Phys. Rev. Appl., vol. 13, p. 044043, 2020.