Mössbauer Spectroscopy as a Tool to Explore Diluted Magnetic Semiconductors

Worldwide, semiconductor spin transfer electronics (spintronics) is of strongly increasing interest. To realize such materials polarized carriers can be injected from a ferromagnetic metal into a diluted magnetic semiconductor (DMS). DMS are “conventional” semiconductors doped with transition metal or rare-earth ions which are diluted within the host matrix and ferromagnetically aligned via an indirect magnetic coupling.

Wide band gap semiconductors like GaN, ZnO, or TiO2 are promising candidates. Doping could be performed by Mn, V, Fe, Co or Ni with concentrations in the range of some %. In the case of 57Fe as doping ion, Mössbauer spectroscopy can be used to investigate how it is built in the host matrix. The 57Fe ion acts both as doping and probe.

In the present study, a survey about Mössbauer spectroscopy as a tool to explore such materials is given. It is very useful however it is insufficient for a full characterization. Other techniques like transmission electron microscopy, Zero-field-cooled/field-cooled SQUID measurements or X-ray diffraction are necessary as complementary methods.