Magnetic properties of low-moment ferrimagnetic Heusler Cr2CoGa thin films grown by molecular beam epitaxy

摘要

Recently, theorists have predicted many materials with a low magnetic momentand large spin-polarization for spintronic applications. These compounds arepredicted to form in the inverse Heusler structure, however, many of thesecompounds have been found to phase segregate. In this study, ordered Cr2CoGathin films were synthesized without phase segregation using molecular beamepitaxy. The present as-grown films exhibit a low magnetic moment fromantiferromagnetically coupled Cr and Co atoms as measured with SQUIDmagnetometry and soft X-ray magnetic circular dichroism. Electricalmeasurements demonstrated a thermally-activated semiconductor-like resistivitywith an activation energy of 87 meV. These results confirm spin gaplesssemiconducting behavior, which makes these thin films well positioned forfuture devices.