Electrical transport properties of ferromagnetic Ga xCr 1-xN thin films

Stephen Y. Wu; Nathan Newman

doi:10.1063/1.2357603

Electrical transport properties of ferromagnetic Ga _xCr _1-xN thin films

Stephen Y. Wu, Nathan Newman

Research output: Contribution to journal › Article › peer-review

12 Scopus citations

Abstract

The authors report the transport properties of ferromagnetic Ga0.97 Cr0.03 N films with a Curie temperature of over 900 K. Samples synthesized under conditions that produce the maximum occupancy of Cr atoms on the Ga site (∼90%) and the maximum ferromagnetic moment of ∼0.6 μB Cr (775 °C growth temperature) exhibit a T-14 dependence of resistivity, indicative of Mott [J. Non-Cryst. Solids 1, 1 (1968)] phonon-assisted variable range hopping between deep level defects. The observation of variable range hopping in ferromagnetic films indicates that ferromagnetism results from a double-exchange-type mechanism. Films grown at higher temperatures (>800 °C) show enhanced Cr segregation, properties associated with percolative transport, and very small, if any, ferromagnetic moments.

Original language	English (US)
Article number	142105
Journal	Applied Physics Letters
Volume	89
Issue number	14
DOIs	https://doi.org/10.1063/1.2357603
State	Published - 2006

ASJC Scopus subject areas

Physics and Astronomy (miscellaneous)

Access to Document

10.1063/1.2357603

Cite this

@article{6c503c3b8ca54185a65c6b004052d12f,

title = "Electrical transport properties of ferromagnetic Ga xCr 1-xN thin films",

abstract = "The authors report the transport properties of ferromagnetic Ga0.97 Cr0.03 N films with a Curie temperature of over 900 K. Samples synthesized under conditions that produce the maximum occupancy of Cr atoms on the Ga site (∼90%) and the maximum ferromagnetic moment of ∼0.6 μB Cr (775 °C growth temperature) exhibit a T-14 dependence of resistivity, indicative of Mott [J. Non-Cryst. Solids 1, 1 (1968)] phonon-assisted variable range hopping between deep level defects. The observation of variable range hopping in ferromagnetic films indicates that ferromagnetism results from a double-exchange-type mechanism. Films grown at higher temperatures (>800 °C) show enhanced Cr segregation, properties associated with percolative transport, and very small, if any, ferromagnetic moments.",

author = "Wu, {Stephen Y.} and Nathan Newman",

note = "Funding Information: This work was supported by the Defense Advanced Research Projects Agency (DARPA) and administered by the Office of Naval Research (Contract No. N00014-02-1-0598). The authors would like to thank John M. Rowell, David Ferry, Mark van Schilfgaarde, Rakesh K. Singh, Hongxue Liu, and Lei Yu for enlightening discussions.",

year = "2006",

doi = "10.1063/1.2357603",

language = "English (US)",

volume = "89",

journal = "Applied Physics Letters",

issn = "0003-6951",

publisher = "American Institute of Physics Publising LLC",

number = "14",

}

TY - JOUR

T1 - Electrical transport properties of ferromagnetic Ga xCr 1-xN thin films

AU - Wu, Stephen Y.

AU - Newman, Nathan

N1 - Funding Information: This work was supported by the Defense Advanced Research Projects Agency (DARPA) and administered by the Office of Naval Research (Contract No. N00014-02-1-0598). The authors would like to thank John M. Rowell, David Ferry, Mark van Schilfgaarde, Rakesh K. Singh, Hongxue Liu, and Lei Yu for enlightening discussions.

PY - 2006

Y1 - 2006

N2 - The authors report the transport properties of ferromagnetic Ga0.97 Cr0.03 N films with a Curie temperature of over 900 K. Samples synthesized under conditions that produce the maximum occupancy of Cr atoms on the Ga site (∼90%) and the maximum ferromagnetic moment of ∼0.6 μB Cr (775 °C growth temperature) exhibit a T-14 dependence of resistivity, indicative of Mott [J. Non-Cryst. Solids 1, 1 (1968)] phonon-assisted variable range hopping between deep level defects. The observation of variable range hopping in ferromagnetic films indicates that ferromagnetism results from a double-exchange-type mechanism. Films grown at higher temperatures (>800 °C) show enhanced Cr segregation, properties associated with percolative transport, and very small, if any, ferromagnetic moments.

AB - The authors report the transport properties of ferromagnetic Ga0.97 Cr0.03 N films with a Curie temperature of over 900 K. Samples synthesized under conditions that produce the maximum occupancy of Cr atoms on the Ga site (∼90%) and the maximum ferromagnetic moment of ∼0.6 μB Cr (775 °C growth temperature) exhibit a T-14 dependence of resistivity, indicative of Mott [J. Non-Cryst. Solids 1, 1 (1968)] phonon-assisted variable range hopping between deep level defects. The observation of variable range hopping in ferromagnetic films indicates that ferromagnetism results from a double-exchange-type mechanism. Films grown at higher temperatures (>800 °C) show enhanced Cr segregation, properties associated with percolative transport, and very small, if any, ferromagnetic moments.

UR - http://www.scopus.com/inward/record.url?scp=33749496714&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33749496714&partnerID=8YFLogxK

U2 - 10.1063/1.2357603

DO - 10.1063/1.2357603

M3 - Article

AN - SCOPUS:33749496714

SN - 0003-6951

VL - 89

JO - Applied Physics Letters

JF - Applied Physics Letters

IS - 14

M1 - 142105

ER -

Electrical transport properties of ferromagnetic Ga _xCr _1-xN thin films

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this