Heterojunction metal-oxide-metal Au-Fe{sub 3}O{sub 4}-Au single nanowire device for spintronics

Journal Article · Thu May 07 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4913891· OSTI ID:22410097

Punnoose, Alex; Hanna, Charles ^[1]; Padture, Nitin P. ^[2]

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1. Department of Physics, Boise State University, Boise, Idaho 83725 (United States)
2. School of Engineering, Brown University, Providence, Rhode Island 02912 (United States)

In this report, we present the synthesis of heterojunction magnetite nanowires in alumina template and describe magnetic and electrical properties from a single nanowire device for spintronics applications. Heterojunction Au-Fe-Au nanowire arrays were electrodeposited in porous aluminum oxide templates, and an extensive and controlled heat treatment process converted Fe segment to nanocrystalline cubic magnetite phase with well-defined Au-Fe{sub 3}O{sub 4} interfaces as confirmed by the transmission electron microscopy. Magnetic measurements revealed Verwey transition shoulder around 120 K and a room temperature coercive field of 90 Oe. Current–voltage (I-V) characteristics of a single Au-Fe{sub 3}O{sub 4}-Au nanowire have exhibited Ohmic behavior. Anomalous positive magnetoresistance of about 0.5% is observed on a single nanowire, which is attributed to the high spin polarization in nanowire device with pure Fe{sub 3}O{sub 4} phase and nanocontact barrier. This work demonstrates the ability to preserve the pristine Fe{sub 3}O{sub 4} and well defined electrode contact metal (Au)–magnetite interface, which helps in attaining high spin polarized current.

• OSTI ID: 22410097
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM OXIDES
CRYSTALS
ELECTRIC POTENTIAL
ELECTRODEPOSITION
FERRITES
GOLD
HEAT TREATMENTS
HETEROJUNCTIONS
INTERFACES
IRON OXIDES
MAGNETITE
MAGNETORESISTANCE
NANOWIRES
POROUS MATERIALS
SPIN ORIENTATION
SYNTHESIS
TEMPERATURE RANGE 0273-0400 K
TRANSMISSION ELECTRON MICROSCOPY