(Color online) Sketch of the contact in (a) the ballistic and (b) the diffusive regime, mimicked by an additional disordered region. The transmission probabilities differ in the two cases.
(a) Circuit diagram of the low-temperature measurements. R is the resistance of the point contact in case of a PCAR measurement. (b) Temperature dependent measurement of the film resistivity in four terminal van-der-Pauw geometry. (c) Point-contact measurement using two contacts on the film surface and two contacts on the superconducting tip.
(Color online) PCAR spectra (Nb/Co2FeSi/GaAs) of the 18 nm thin samples. The spectra are corrected by a series resistance Rs , normalized by the resistance Rn , and offset for clarity. The black lines are best fits calculated with the diffusive BTK model. The values for the polarization P and the contact quality Z are plotted in the insets. An extrapolation to Z = 0 estimates the spin polarization at the Fermi energy.
(Color online) PCAR measurements (Nb/Co2FeSi/GaAs) on the 48 nm thick samples.
(Color online) Temperature dependent resistivities of the three investigated 18 nm Co2FeSi films (PDI-1 to PDI-3). At 77 K results from earlier measurements at liquid Nitrogen temperature are indicated by black crosses.
Substrate temperature at deposition, film thickness, spin polarization, and resistivity at T = 2 K of the Co2FeSi films.
Article metrics loading...
Full text loading...