High spin polarization in Co2CrAl-Cr superlattice

The electronic structure, magnetic properties and interface effects in Co2CrAl-Cr superstructures have been investigated by the use of first principle calculations. The results show that at the interface, a large magnetic moment and a high spin polarization can be induced by a strong ferromagnetic exchange interaction at the Cr-Co interface. However, at the CrAl-Cr interface, both the magnetic moment and the spin polarization of the Cr atoms are decreased due to a Cr-Cr antiferromagnetic interaction. It can also be found that the interface effect is only a short range effect. So, high spin polarization in Co2CrAl-Cr superlattice can be obtained. Based on this theoretical analysis, a large giant magnetoresistance effect can be expected in the Co2CrAl-Cr superlattices with proper thickness of the Cr spacer layers.