Spin-polarized transport in magnetically assembled carbon nanotube spin valves

Spin polarized transport over $5μm$ long carbon nanotubes (CNTs) is observed in magnetically assembled spin valves with electrochemically deposited ferromagnetic (FM) electrodes. An annealing procedure is developed to produce stable devices with highly transmissive FM/CNT contacts. The devices exhibit magnetoresistance (MR) with magnitudes up to 4%, and the sign of MR is consistently negative. The temperature dependence is investigated and MR is observed up to $14K$⁠. Bias dependence is also investigated, with MR persisting up to $∼300mV$⁠.