Thermal annealing enhancement of Josephson critical currents in ferromagnetic CoFeB

Abstract

The electrical and structural properties of Co40Fe40B20 (CoFeB) alloy are tunable with thermal annealing. This is key in the optimization of CoFeB-based spintronic devices, where the advantageously low magnetic coercivity, high spin polarization, and controllable magnetocrystalline anisotropy are utilised. So far, there has been no report on superconducting devices based on CoFeB. Here, we report Nb/CoFeB/Nb Josephson devices and demonstrate an enhancement of the critical current by up to 700% following thermal annealing due to increased structural ordering of the CoFeB. The results demonstrate that CoFeB is a promising material for the development of superconducting spintronic devices.

arXiv comment12 pages, 5 figures

References in corpus (9)

• Proximity effects in superconductor-ferromagnet heterostructures
• Critical Current Oscillations in Strong Ferromagnetic Pi-Junctions
• Oscillations of the superconducting critical current in Nb-Cu-Ni-Cu-Nb junctions
• Half-integer Shapiro steps at the 0-pi crossover of a ferromagnetic Josephson junction
• Ferromagnetic Josephson switching device with high characteristic voltage
• Theoretical Model of Superconducting Spintronic SIsFS Devices
• Peculiar properties of the Josephson junction at the transition from 0 to Pi state
• Quantitative analysis of proximity effect in $Nb/C{o}_{60}F{e}_{40}$, Nb/Ni, and $Nb/C{u}_{40}N{i}_{60}$ bilayers
• Direct measurements of the penetration depth in a superconducting film using magnetic force microscopy

Cited by in corpus (1)

• Ferromagnetic Materials for Josephson π Junctions