Four-terminal nonlocal signals in lateral spin transport devices with variously ordered Co2FeAl0.5Si0.5 full-Heusler alloy electrodes

The structural ordering of the Co2FeAl0.5Si0.5 (CFAS) full-Heusler alloy, the electrical transport properties, and the four-terminal (4T) nonlocal signals were investigated in lateral spin transport devices with CFAS/n-GaAs Schottky tunnel junctions as a function of the deposition temperature of CFAS (T-CFAS). The 4T nonlocal signals increased with increasing T-CFAS, in contrast to the trend in three-terminal Hanle measurements [Jpn. J. Appl. Phys., Part 1 52, 063001 (2013)]. No relationship between interface resistance and 4T nonlocal signal was confirmed, indicating that conductance mismatch problems did not affect the tendency of signal values. (C) 2013 AIP Publishing LLC.