Please use this identifier to cite or link to this item:
|Title:||Spin-injection efficiency and magnetoresistance in a ferromagnet-semiconductor-ferromagnet trilayer|
|Citation:||Agrawal, S., Jalil, M.B.A., Teo, K.L., Liew, Y.F. (2005-05-15). Spin-injection efficiency and magnetoresistance in a ferromagnet-semiconductor-ferromagnet trilayer. Journal of Applied Physics 97 (10) : -. ScholarBank@NUS Repository. https://doi.org/10.1063/1.1886886|
|Abstract:||We present a drift-diffusion transport model to evaluate the spin-injection efficiency η and magnetoresistance (MR) ratio in a ferromagnetic (FM) metal-semiconductor (SC)-FM metal trilayer structure. This model takes into account the differential interfacial resistances (IR) for spin-up and spin-down electrons and spin relaxation within the SC layer. The electrochemical potential μ for both spin directions is analytically solved and expressions for η, spin polarization of current P, and the MR ratio are derived. The presence of IR at the FM-SC boundary is crucial for generating a large spin splitting of μ, and consequently a high injection efficiency η. The IR needs to fulfill the requirements of (i) of a large magnitude comparable to the resistance of the SC layer and (ii) high asymmetry with respect to the two spin directions. To increase η from 1% to 30%, we require a large IR of 10-5 Ω cm2 and a spin asymmetry of 10:1. There are more stringent requirements for achieving a high MR ratio. An IR of 10-5 Ω cm2 and FM contact polarization Pc of 80% will only yield an MR ratio of 10%. We require a much larger IR ≥ 10-4 Ω cm2 or virtually half-metallic contacts, i.e., Pc of ~100% to achieve high MR ratio exceeding 50%. © 2005 American Institute of Physics.|
|Source Title:||Journal of Applied Physics|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Jan 16, 2019
WEB OF SCIENCETM
checked on Jan 9, 2019
checked on Jan 12, 2019
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.