Tuning optical and ferromagnetic properties of thin GdN films by nitrogen-vacancy centers

  • Reddithota Vidyasagar
  • Shinya Kitayama
  • Hiroaki Yoshitomi
  • Takashi Kita
  • Takahiro Sakurai
  • Hitoshi Ohta
Regular Article
Part of the following topical collections:
  1. Topical issue: Excitonic Processes in Condensed Matter, Nanostructured and Molecular Materials

Abstract

AlN/GdN/AlN double heterostructures were grown on c-sapphire substrates using a reactive rf sputtering method under high vacuum conditions. The optical absorption spectrum of the GdN shows a clear fundamental band edge of GdN around 800 nm; this transition is attributed to the minority spin band energy of GdN at the X point. Nitrogen vacancy centers cause a blue-shift of the optical band edge of GdN, which could be ascribed to both the band filling, and the electron-hole interactions resulting from the free carriers generated by nitrogen vacancies. Temperature-dependent magnetization measurements demonstrate a clear change in the magnetization values of GdN with respect to the N2 partial pressure. Nitrogen vacancy centers in the thin GdN film raise the Curie temperature from 31 K to 39 K, which has been accurately measured by the Arrott plots.

Keywords

Topical issue: Excitonic Processes in Condensed Matter, Nanostructured and Molecular Materials. Guest editors: Maria Antonietta Loi, Jasper Knoester and Paul H. M. van Loosdrecht 

Copyright information

© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Reddithota Vidyasagar
    • 1
  • Shinya Kitayama
    • 1
  • Hiroaki Yoshitomi
    • 1
  • Takashi Kita
    • 1
  • Takahiro Sakurai
    • 2
  • Hitoshi Ohta
    • 3
  1. 1.Department of Electrical and Electronic EngineeringGraduate School of Engineering, Kobe UniversityKobeJapan
  2. 2.Center for Support to Research and Education Activities, Kobe UniversityKobeJapan
  3. 3.Molecular Photoscience Research Center and Graduate School of Science, Kobe UniversityKobeJapan

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