Transport spin polarization of the rare-earth transition-metal alloy Co1−xGdx

Abstract

We present point-contact Andreev reflection (PCAR) measurements of the transport spin polarization of ferrimagnetic Co${}_{1\ensuremath{-}x}$Gd${}_{x}$ alloys. At the compensation point of the alloy, where the magnetization of the independent Co and Gd subnetworks are equal and the net magnetization of the alloy is close to zero, there remains a finite transport spin polarization. The composition dependence of the transport spin polarization measured by PCAR is quite different from that of the tunneling spin polarization.