Recent progress towards the development of ferromagnetic nitride semiconductors for spintronic applications

Nathan Newman, S. Y. Wu, H. X. Liu, J. Medvedeva, Lin Gu, Rakesh Singh, Z. G. Yu, I. L. Krainsky, S. Krishnamurthy, David Smith, A. J. Freeman, M. Van Schilfgaarde

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

This article describes progress towards producing prototype magnetoelectronic structures based on III-N semiconductor materials. We focus on the materials properties connected with the key physical phenomena underlying potential spintronic devices: producing, injecting, transporting, manipulating and detecting spin-polarized electron populations. Our experiments have shown that the maximum magnetic moment is realized for a composition of Ga 0.97Cr 0.03N and a substrate growth temperature of ∼ 1050 K. Ion channeling experiments show that ∼90% of Cr sits substitutionally on the cation site. The highest measured magnetization was 1.8μ B/Cr atom (∼60% of the expected moment from band theory for ideal material) with the Curie temperature over ∼900 K. This strongly suggests a link between the Cr Ga impurity band and ferromagnetism and suggests that a double-exchange-like mechanism is responsible for the ferromagnetic ordering. The transport properties of spin-polarized charge carriers were modeled theoretically taking into account both the Elliott - Yafet and the D'yakonov-Perel' scattering mechanisms. We include the spin-orbit interaction in the unperturbed Hamiltonian and treat scattering by ionized impurities and phonons as a perturbation. Our numerical calculations predict two orders of magnitude longer electron spin relaxation times and an order of magnitude shorter hole spin relaxation times in GaN than in GaAs. First-principles electronic structure calculations predict that efficient spin injection can be achieved using a ferromagnetic GaN : Cr electrode in conjunction with an AlN tunnel barrier. In this structure, the electrode is found to be half-metallic up to the interface and is thus a candidate for high-efficiency magnetoelectronic devices.

Original languageEnglish (US)
Pages (from-to)2729-2737
Number of pages9
JournalPhysica Status Solidi (A) Applications and Materials Science
Volume203
Issue number11
DOIs
StatePublished - Sep 2006

Fingerprint

Magnetoelectronics
Nitrides
nitrides
Semiconductor materials
Relaxation time
Scattering
Impurities
Hamiltonians
Electrodes
Electrons
relaxation time
Ferromagnetism
Growth temperature
Phonons
Curie temperature
Magnetic moments
Charge carriers
impurities
Transport properties
Electronic structure

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Recent progress towards the development of ferromagnetic nitride semiconductors for spintronic applications. / Newman, Nathan; Wu, S. Y.; Liu, H. X.; Medvedeva, J.; Gu, Lin; Singh, Rakesh; Yu, Z. G.; Krainsky, I. L.; Krishnamurthy, S.; Smith, David; Freeman, A. J.; Van Schilfgaarde, M.

In: Physica Status Solidi (A) Applications and Materials Science, Vol. 203, No. 11, 09.2006, p. 2729-2737.

Research output: Contribution to journalArticle

Newman, N, Wu, SY, Liu, HX, Medvedeva, J, Gu, L, Singh, R, Yu, ZG, Krainsky, IL, Krishnamurthy, S, Smith, D, Freeman, AJ & Van Schilfgaarde, M 2006, 'Recent progress towards the development of ferromagnetic nitride semiconductors for spintronic applications', Physica Status Solidi (A) Applications and Materials Science, vol. 203, no. 11, pp. 2729-2737. https://doi.org/10.1002/pssa.200669636
Newman, Nathan ; Wu, S. Y. ; Liu, H. X. ; Medvedeva, J. ; Gu, Lin ; Singh, Rakesh ; Yu, Z. G. ; Krainsky, I. L. ; Krishnamurthy, S. ; Smith, David ; Freeman, A. J. ; Van Schilfgaarde, M. / Recent progress towards the development of ferromagnetic nitride semiconductors for spintronic applications. In: Physica Status Solidi (A) Applications and Materials Science. 2006 ; Vol. 203, No. 11. pp. 2729-2737.
@article{49362420f24a4fd3982176c7ba101af2,
title = "Recent progress towards the development of ferromagnetic nitride semiconductors for spintronic applications",
abstract = "This article describes progress towards producing prototype magnetoelectronic structures based on III-N semiconductor materials. We focus on the materials properties connected with the key physical phenomena underlying potential spintronic devices: producing, injecting, transporting, manipulating and detecting spin-polarized electron populations. Our experiments have shown that the maximum magnetic moment is realized for a composition of Ga 0.97Cr 0.03N and a substrate growth temperature of ∼ 1050 K. Ion channeling experiments show that ∼90{\%} of Cr sits substitutionally on the cation site. The highest measured magnetization was 1.8μ B/Cr atom (∼60{\%} of the expected moment from band theory for ideal material) with the Curie temperature over ∼900 K. This strongly suggests a link between the Cr Ga impurity band and ferromagnetism and suggests that a double-exchange-like mechanism is responsible for the ferromagnetic ordering. The transport properties of spin-polarized charge carriers were modeled theoretically taking into account both the Elliott - Yafet and the D'yakonov-Perel' scattering mechanisms. We include the spin-orbit interaction in the unperturbed Hamiltonian and treat scattering by ionized impurities and phonons as a perturbation. Our numerical calculations predict two orders of magnitude longer electron spin relaxation times and an order of magnitude shorter hole spin relaxation times in GaN than in GaAs. First-principles electronic structure calculations predict that efficient spin injection can be achieved using a ferromagnetic GaN : Cr electrode in conjunction with an AlN tunnel barrier. In this structure, the electrode is found to be half-metallic up to the interface and is thus a candidate for high-efficiency magnetoelectronic devices.",
author = "Nathan Newman and Wu, {S. Y.} and Liu, {H. X.} and J. Medvedeva and Lin Gu and Rakesh Singh and Yu, {Z. G.} and Krainsky, {I. L.} and S. Krishnamurthy and David Smith and Freeman, {A. J.} and {Van Schilfgaarde}, M.",
year = "2006",
month = "9",
doi = "10.1002/pssa.200669636",
language = "English (US)",
volume = "203",
pages = "2729--2737",
journal = "Physica Status Solidi (A) Applications and Materials Science",
issn = "1862-6300",
publisher = "Wiley-VCH Verlag",
number = "11",

}

TY - JOUR

T1 - Recent progress towards the development of ferromagnetic nitride semiconductors for spintronic applications

AU - Newman, Nathan

AU - Wu, S. Y.

AU - Liu, H. X.

AU - Medvedeva, J.

AU - Gu, Lin

AU - Singh, Rakesh

AU - Yu, Z. G.

AU - Krainsky, I. L.

AU - Krishnamurthy, S.

AU - Smith, David

AU - Freeman, A. J.

AU - Van Schilfgaarde, M.

PY - 2006/9

Y1 - 2006/9

N2 - This article describes progress towards producing prototype magnetoelectronic structures based on III-N semiconductor materials. We focus on the materials properties connected with the key physical phenomena underlying potential spintronic devices: producing, injecting, transporting, manipulating and detecting spin-polarized electron populations. Our experiments have shown that the maximum magnetic moment is realized for a composition of Ga 0.97Cr 0.03N and a substrate growth temperature of ∼ 1050 K. Ion channeling experiments show that ∼90% of Cr sits substitutionally on the cation site. The highest measured magnetization was 1.8μ B/Cr atom (∼60% of the expected moment from band theory for ideal material) with the Curie temperature over ∼900 K. This strongly suggests a link between the Cr Ga impurity band and ferromagnetism and suggests that a double-exchange-like mechanism is responsible for the ferromagnetic ordering. The transport properties of spin-polarized charge carriers were modeled theoretically taking into account both the Elliott - Yafet and the D'yakonov-Perel' scattering mechanisms. We include the spin-orbit interaction in the unperturbed Hamiltonian and treat scattering by ionized impurities and phonons as a perturbation. Our numerical calculations predict two orders of magnitude longer electron spin relaxation times and an order of magnitude shorter hole spin relaxation times in GaN than in GaAs. First-principles electronic structure calculations predict that efficient spin injection can be achieved using a ferromagnetic GaN : Cr electrode in conjunction with an AlN tunnel barrier. In this structure, the electrode is found to be half-metallic up to the interface and is thus a candidate for high-efficiency magnetoelectronic devices.

AB - This article describes progress towards producing prototype magnetoelectronic structures based on III-N semiconductor materials. We focus on the materials properties connected with the key physical phenomena underlying potential spintronic devices: producing, injecting, transporting, manipulating and detecting spin-polarized electron populations. Our experiments have shown that the maximum magnetic moment is realized for a composition of Ga 0.97Cr 0.03N and a substrate growth temperature of ∼ 1050 K. Ion channeling experiments show that ∼90% of Cr sits substitutionally on the cation site. The highest measured magnetization was 1.8μ B/Cr atom (∼60% of the expected moment from band theory for ideal material) with the Curie temperature over ∼900 K. This strongly suggests a link between the Cr Ga impurity band and ferromagnetism and suggests that a double-exchange-like mechanism is responsible for the ferromagnetic ordering. The transport properties of spin-polarized charge carriers were modeled theoretically taking into account both the Elliott - Yafet and the D'yakonov-Perel' scattering mechanisms. We include the spin-orbit interaction in the unperturbed Hamiltonian and treat scattering by ionized impurities and phonons as a perturbation. Our numerical calculations predict two orders of magnitude longer electron spin relaxation times and an order of magnitude shorter hole spin relaxation times in GaN than in GaAs. First-principles electronic structure calculations predict that efficient spin injection can be achieved using a ferromagnetic GaN : Cr electrode in conjunction with an AlN tunnel barrier. In this structure, the electrode is found to be half-metallic up to the interface and is thus a candidate for high-efficiency magnetoelectronic devices.

UR - http://www.scopus.com/inward/record.url?scp=33749066506&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33749066506&partnerID=8YFLogxK

U2 - 10.1002/pssa.200669636

DO - 10.1002/pssa.200669636

M3 - Article

VL - 203

SP - 2729

EP - 2737

JO - Physica Status Solidi (A) Applications and Materials Science

JF - Physica Status Solidi (A) Applications and Materials Science

SN - 1862-6300

IS - 11

ER -