Spin and size-dependent effects in semimagnetic semiconductor nanostructures

The technique of pulsed laser deposition has been applied for growth of Cd1−xMnxTe thin films and CdTe/Cd1−xMnxTe quantum well structures. Different materials (silicon, glass, sapphire) have been used as substrates which where heated to 300 °C during deposition process. X-ray diffraction, scanning electron microscopy, optical absorption and Faraday rotation spectroscopy have been used to characterize the obtained thin films and quantum structures. The observation of exciton peaks in the absorption spectra at low temperatures demonstrates the high quality of the deposited layers. The Faraday rotation spectra of the thin films exhibit peculiarities typical for bulk semimagnetic semiconductors because of strong spin-exchange interaction between band carriers and magnetic ions. For the superlattice structures of CdTe/Cd1−xMnxTe, the peak value of the Faraday rotation increases and its position moves toward higher energies with decreasing barrier thickness because of exciton confinement effect.