Contribution of Mössbauer Spectroscopy to the Exploration of Diluted Magnetic Semiconductors


Contribution of Mössbauer Spectroscopy to the Exploration of Diluted Magnetic Semiconductors

Reuther, H.

Worldwide, semiconductor spin transfer electronics (spintronics) is of strongly increasing interest. One intention is the use of the spin for data storage to increase the possible storage density, another one is to overcome the fundamental limits of the computing speed. To realize such devices 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. For applications, it is important that such DMS could be used at practical temperatures, i.e. above room temperature, and that they can base upon an already existing materials technology.

From theory, wide band gap semiconductors like GaN, ZnO, InN, AlP or SiC are the most promising candidates. Doping could be performed by Mn, V, Fe, Co or Ni with concentrations in the range of some %. The magnetism may originate either from a more or less random alloy in which the doping ion substitutes a host atom as interstitial or from small clusters. 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 ion implantation is used as doping technique. 57Fe ions were implanted into GaN, ZnO and SiC. The produced layers were investigated by Mössbauer spectroscopy however this method is insufficient for a full characterization. Therefore, samples were studied by transmission electron microscopy, Auger electron spectroscopy, Zero-field-cooled/field-cooled SQUID measurements and by X-ray diffraction too. Depending on the implantation temperature and the annealing conditions diluted magnetic semiconductors could be obtained.

  • Invited lecture (Conferences)
    Sixth workshop on Mössbauer spectroscopy Seeheim, 07.-11.06.2006, Seeheim, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-8559
Publ.-Id: 8559