Spin polarization of quaternary Co_2Cr_(1-x)Fe_xAl Heusler alloys

摘要

Point contact Andreev reflection measurements of Co_2Cr_(1-x)Fe_xAl Heusler alloys showed that the spin polarization P decreases with x from P=0.62 for x=0.0 to P=0.54 for x=0.4 and then increases slightly to P=0.56 for x=1.0. The deviation in P of the samples with x=0.0 and 0.4 from the theoretical predictions (P > 0.9) can be accounted to the phase separation, whereas the deviation in P of the sample with x=1.0 from the theoretical predictions (P=0.3) suggests the lack of accuracy in density of state calculations.