The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

MnAs dots grown on GaN( 000(1)over-bar)-(1x1) surface

Author

  • I. A. Kowalik
  • B. J. Kowalski
  • R. J. Iwanowski
  • K. Kopalko
  • E. Lusakowska
  • M. Sawicki
  • Janusz Sadowski
  • M. Adell
  • I. Grzegory
  • S. Porowski

Summary, in English

MnAs has been grown by means of MBE on the GaN(000 (1) over bar)-(1x1) surface. Two options of initiating the crystal growth were applied: (a) a regular MBE procedure (manganese and arsenic were delivered simultaneously) and (b) subsequent deposition of manganese and arsenic layers. It was shown that spontaneous formation of MnAs dots with the surface density of 1x10(11) cm(-2) and 2.5x10(11) cm(-2), respectively (as observed by atomic force microscopy), occurred for the layer thickness higher than 5 ML. Electronic structure of the MnAs/GaN systems was studied by resonant photoemission spectroscopy. That led to determination of the Mn 3d-related contribution to the total density of states distribution of MnAs. It has been proven that the electronic structures of the MnAs dots grown by the two procedures differ markedly. One corresponds to metallic, ferromagnetic NiAs-type MnAs, the other is similar to that reported for half-metallic zinc-blende MnAs. Both systems behave superparamagnetically (as revealed by magnetization measurements), but with both the blocking temperatures and the intradot Curie temperatures substantially different. The intradot Curie temperature is about 260 K for the former system while markedly higher than room temperature for the latter one. Relations between growth process, electronic structure, and other properties of the studied systems are discussed. Possible mechanisms of half-metallic MnAs formation on GaN are considered.

Department/s

Publishing year

2007

Language

English

Publication/Series

Physical Review B (Condensed Matter and Materials Physics)

Volume

75

Issue

23

Document type

Journal article

Publisher

American Physical Society

Topic

  • Physical Sciences
  • Natural Sciences

Status

Published

ISBN/ISSN/Other

  • ISSN: 1098-0121