Report

A Group-IV Ferromagnetic Semiconductor: MnxGe1−x

See allHide authors and affiliations

Science  25 Jan 2002:
Vol. 295, Issue 5555, pp. 651-654
DOI: 10.1126/science.1066348

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

We report on the epitaxial growth of a group-IV ferromagnetic semiconductor, MnxGe1−x, in which the Curie temperature is found to increase linearly with manganese (Mn) concentration from 25 to 116 kelvin. The p-type semiconducting character and hole-mediated exchange permit control of ferromagnetic order through application of a ±0.5-volt gate voltage, a value compatible with present microelectronic technology. Total-energy calculations within density-functional theory show that the magnetically ordered phase arises from a long-range ferromagnetic interaction that dominates a short-range antiferromagnetic interaction. Calculated spin interactions and percolation theory predict transition temperatures larger than measured, consistent with the observed suppression of magnetically active Mn atoms and hole concentration.

  • * Present address: School of Physics and CSCMR, Seoul National University, Seoul 151-747, Korea.

  • Present address: Micron Technology, Boise, ID 33707, USA.

  • Present address: Seagate Technology, Pittsburgh, PA 15203, USA.

  • § Present address: Boeing Satellite Systems, El Segundo, CA 90009, USA.

  • || To whom correspondence should be addressed. E-mail: jonker{at}nrl.navy.mil

View Full Text