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Title: A comparative study of three-terminal Hanle signals in CoFe/SiO{sub 2}/n{sup +}-Si and Cu/SiO{sub 2}/n{sup +}-Si tunnel junctions

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4940120· OSTI ID:22489321
;  [1];  [2]; ;  [3]
  1. School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005 (Korea, Republic of)
  2. Grünberg Center for Magnetic Nanomaterials, Gwangju Institute of Science and Technology (GIST), Gwangju 61005 (Korea, Republic of)
  3. School of Materials Science and Engineering-Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology, Ulsan 44919 (Korea, Republic of)

We performed three-terminal (3T) Hanle measurement for two types of sample series, CoFe/SiO{sub 2}/n{sup +}-Si and Cu/SiO{sub 2}/n{sup +}-Si, with various tunnel resistances. Clear Hanle signal and anomalous scaling between spin resistance-area product and tunnel resistance-area product were observed in CoFe/SiO{sub 2}/n{sup +}-Si devices. In order to explore the origin of the Hanle signal and the impurity-assisted tunneling effect on the Hanle signal in our devices, Hanle measurement in Cu/SiO{sub 2}/n{sup +}-Si devices was performed as well. However, no detectable Hanle signal was observed in Cu/SiO{sub 2}/n{sup +}-Si, even though a lot of samples with various tunnel resistances were studied in wide temperature and bias voltage ranges. Through a comparative study, it is found that the impurity-assisted tunneling magnetoresistance mechanism would not play a dominant role in the 3T Hanle signal in CoFe/SiO{sub 2}/n{sup +}-Si tunnel junctions, where the SiO{sub 2} was formed by plasma oxidation to minimize impurities.

OSTI ID:
22489321
Journal Information:
Applied Physics Letters, Vol. 108, Issue 3; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English