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Magnetoelectric properties of 500 nm Cr
2
O
3
films
P. Borisov,
1
a
T. Ashida,
2
T. Nozaki,
2
M. Sahashi,
2
D. Lederman
1,3
1
Department of Physics and Astronomy, West Virginia University, Morgantown
WV 26506-6315, USA
2
Department of Electronic Engineering, Tohoku University, Sendai, 980-0845, Ja-
pan
3
Department of Physics, University of California, Santa Cruz, CA 95064, USA
Abstract
The linear magnetoelectric effect was measured in 500 nm Cr
2
O
3
films grown by rf
sputtering on Al
2
O
3
substrates between top and bottom thin film Pt electrodes.
Magnetoelectric susceptibility was measured directly by applying an AC electric
field and measuring the induced AC magnetic moment using superconducting quan-
tum interference device magnetometry. A linear dependence of the induced AC
magnetic moment on the AC electric field amplitude was found. The temperature
dependence of the magnetoelectric susceptibility agreed qualitatively and quantita-
tively with prior measurements of bulk single crystals, but the characteristic tem-
peratures of the film were lower than those of single crystals. It was also possible to
reverse the sign of the magnetoelectric susceptibility by reversing the sign of the
magnetic field applied during cooling through the Néel temperature. A competition
between total magnetoelectric and Zeeman energies is proposed to explain the dif-
ference between film and bulk Cr
2
O
3
regarding the cooling field dependence of the
magnetoelectric effect.
a
Email of corresponding author: pavel.borisov@mail.wvu.edu
