High Curie temperature in Eu-doped GaN caused by volume-compensated Ga-vacancy

Akira Masago, Hikari Shinya, Tetsuya Fukushima, Kazunori Sato, Hiroshi Katayama-Yoshida

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1 Citation (Scopus)

Abstract

This study computationally demonstrates that room-temperature ferromagnetism, which has been experimentally observed in Eu-doped GaN, is induced by holes in N 2p states (i.e., Zener's double exchange interaction) that arise on the assumption that Ga vacancies appear as a result of the introduction of Eu ions (i.e., volume compensation). The calculated Curie temperature (TC) suddenly increases over a certain range of Ga-vacancy concentrations and gradually increases with an increasing concentration of Eu ions. High TC above room temperature is dominated by Zener's double exchange mechanism in partially occupied N 2p hole-states, which itinerate throughout the whole crystals, and low TC is dominated by Zener's p-f exchange mechanism in Eu 4f and N 2p hybridization. We can reasonably explain the surprising experimental data of 4000 μB per Gd atom in Gd-doped GaN reported by Dhar et al. [Phys. Rev. Lett. 94, 037205 (2005)].

Original languageEnglish
Article number025216
JournalAIP Advances
Volume10
Issue number2
DOIs
Publication statusPublished - 2020 Feb 1

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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