Room temperature ferromagnetism in epitaxial Cr{sub 2}O{sub 3} thin films grown on r-sapphire

Journal Article · Thu May 21 04:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4921435· OSTI ID:22410211

Punugupati, Sandhyarani; Narayan, Jagdish; Hunte, Frank ^[1]

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1. Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

We report on the epitaxial growth and magnetic properties of Cr{sub 2}O{sub 3} thin films grown on r-sapphire substrate using pulsed laser deposition. The X-ray diffraction (XRD) (2θ and Φ) and TEM characterization confirm that the films are grown epitaxially. The r-plane (011{sup ¯}2) of Cr{sub 2}O{sub 3} grows on r-plane of sapphire. The epitaxial relations can be written as [011{sup ¯}2] Cr{sub 2}O{sub 3} ‖ [011{sup ¯}2] Al{sub 2}O{sub 3} (out-of-plane) and [1{sup ¯}1{sup ¯}20] Cr{sub 2}O{sub 3} ‖ [1{sup ¯}1{sup ¯}20] Al{sub 2}O{sub 3} (in-plane). The as-deposited films showed ferromagnetic behavior up to 400 K but ferromagnetism almost vanishes with oxygen annealing. The Raman spectroscopy data together with strain measurements using high resolution XRD indicate that ferromagnetism in r-Cr{sub 2}O{sub 3} thin films is due to the strain caused by defects, such as oxygen vacancies.

• OSTI ID: 22410211
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 19 Vol. 117; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM OXIDES
ANNEALING
CHROMATES
CHROMIUM OXIDES
ENERGY BEAM DEPOSITION
EPITAXY
FERROMAGNETISM
LASER RADIATION
MAGNETIC PROPERTIES
PULSED IRRADIATION
RAMAN SPECTROSCOPY
SAPPHIRE
STRAINS
SUBSTRATES
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
VACANCIES
X-RAY DIFFRACTION