Room-temperature tunnel magnetoresistance across biomolecular tunnel junctions based on ferritin. (20th May 2021)

• Record Type: Journal Article
• Authors: Karuppannan, Senthil Kumar; Pasula, Rupali Reddy; Herng, Tun Seng; Ding, Jun; Chi, Xiao; Barco, Enrique Del; Roche, Stephan; Yu, Xiaojiang; Yakovlev, Nikolai; Lim, Sierin; Nijhuis, Christian A
• Is Part Of: JPhys materials. Volume 4:Number 3(2021)
• Publication Date: 2021-05-20
• Subjects: ferritin -- tunneling magnetoresistance -- magnons -- EGaIn -- biomolecular tunnel junction -- ferromagnetic/molecule interface; Solid state physics -- Periodicals; Materials science -- Periodicals; 530.41
• DOI: 10.1088/2515-7639/abfa79
• Languages: English
• ISSNs: 2515-7639

Abstract

Abstract: We report exceptionally large tunnel magnetoresistance (TMR) for biomolecular tunnel junctions based on ferritins immobilized between Ni and EGaIn electrodes. Ferritin stores iron in the form of ferrihydrite nanoparticles (NPs) and fulfills the following roles: (a) it dictates the tunnel barrier, (b) it magnetically decouples the NPs from the ferromagnetic (FM) electrode, (c) it stabilizes the NPs, and (d) it acts as a spin filter reducing the complexity of the tunnel junctions since only one FM electrode is required. The mechanism of charge transport is long-range tunneling which results in TMR of 60 ± 10% at 200 K and 25 ± 5% at room temperature. We propose a magnon-assisted transmission to explain the substantially larger TMR switching fields (up to 1 Tesla) than the characteristic coercive fields (a few Gauss) of ferritin ferrihydrite particles at T < 20 K. These results highlight the genuine potential of biomolecular tunnel junctions in designing functional nanoscale spintronic devices.