Sources for ferromagnetism in ion implanted ZnO


Sources for ferromagnetism in ion implanted ZnO

Potzger, K.; Zhou, S.

The combination of magnetic and semiconducting properties in oxides is currently one of most popular fields in materials research. Besides the expected gain of knowledge about basic physics, such materials have a large application potential in spin electronics. We present a summary of our results on transition metal doping of ZnO single crystals and thin films by means of ion implantation. We found that none of the samples investigated represents a diluted magnetic semiconductor as predicted by theory [1]. The observed ferromagnetism mainly originates from secondary phase formation (metals or inverted spinel ferrites). We highlight the suppression of secondary phase formation by means of deliberately lowering the crystalline quality prior to the doping. Moreover, bombardment with transition metal ions leads to defects which create weak ferromagnetism without participation of the transition metal implanted. We discuss the possibility that such defects are also responsible for ferromagnetism observed in transition metal doped ZnO thin films. Thus, interpretations of ferromagnetic DMS reported in the past are often misleading.

[1] K. Sato and H. Katayama-Yoshida, Physica E 10, 251 (2001).

Keywords: ion implantation; zno; DMS

  • Lecture (Conference)
    IBMM 08 - 16th International Conference on Ion Beam Modification of Materials, 31.08.-5.9.2008, Dresden, Germany

Permalink: https://www.hzdr.de/publications/Publ-11170
Publ.-Id: 11170