Density dependence of zinc-blende MnAs dots studied by X-ray absorption spectroscopy and X-ray magnetic circular dichroism

Density-dependent electronic structure of zinc-blende-type MnAs dots on GaAs(001) studied byin situphotoemission spectroscopy

“…Since the samples are thin films and the magnetic atoms are dilute, it is difficult to characterize the magnetic properties using conventional magnetic measurements. In the magnetic circular dichroism study in the Mn 2p core-level absorption, 22 it was revealed that the high-density samples behave ferromagnetically, although the samples with dot density less than the percolation density ͑3 ϫ 10 12 cm −2 ͒ show nonferromagnetic (superparamagnetic) behavior. According to the band-structure calculation, the zinc-blende-type MnAs is predicted to be a halfmetallic ferromagnet.…”