TY - JOUR
T1 - Quadratic magnetoelectric effect during field cooling in sputter grown Cr2 O3 films
AU - Al-Mahdawi, Muftah
AU - Nozaki, Tomohiro
AU - Oogane, Mikihiko
AU - Imamura, Hiroshi
AU - Ando, Yasuo
AU - Sahashi, Masashi
N1 - Funding Information:
The authors thank M. Nemoto (Technical Division of Tohoku University) for technical support in the Raman spectroscopic measurements. This work was partially supported by the Center for Science and Innovation in Spintronics (CSIS) and Center for Spintronics Research Network (CSRN), Tohoku University, and the ImPACT Program of the Council for Science, Technology and Innovation (Cabinet Office, Government of Japan).
Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/9
Y1 - 2021/9
N2 - Cr2O3 is the archetypal magnetoelectric (ME) material, which has a linear coupling between electric and magnetic polarizations. Quadratic ME effects are forbidden for the magnetic point group of Cr2O3, due to space-time inversion symmetry. In Cr2O3 films grown by sputtering, we find a signature of a quadratic ME effect that is not found in bulk single crystals. We use Raman spectroscopy and magnetization measurements to deduce the removal of space-time symmetry and corroborate the emergence of the quadratic ME effect. We propose that metastable site-selective trace dopants remove the space, time, and space-time inversion symmetries from the original magnetic point group of bulk Cr2O3. We include the quadratic ME effect in a model describing the switching process during ME field cooling and estimate the effective quadratic susceptibility value. The quadratic magnetoelectric effect in a uniaxial antiferromagnet is promising for multifunctional antiferromagnetic and magnetoelectric devices that can incorporate optical, strain-induced, and multiferroic effects.
AB - Cr2O3 is the archetypal magnetoelectric (ME) material, which has a linear coupling between electric and magnetic polarizations. Quadratic ME effects are forbidden for the magnetic point group of Cr2O3, due to space-time inversion symmetry. In Cr2O3 films grown by sputtering, we find a signature of a quadratic ME effect that is not found in bulk single crystals. We use Raman spectroscopy and magnetization measurements to deduce the removal of space-time symmetry and corroborate the emergence of the quadratic ME effect. We propose that metastable site-selective trace dopants remove the space, time, and space-time inversion symmetries from the original magnetic point group of bulk Cr2O3. We include the quadratic ME effect in a model describing the switching process during ME field cooling and estimate the effective quadratic susceptibility value. The quadratic magnetoelectric effect in a uniaxial antiferromagnet is promising for multifunctional antiferromagnetic and magnetoelectric devices that can incorporate optical, strain-induced, and multiferroic effects.
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U2 - 10.1103/PhysRevMaterials.5.094406
DO - 10.1103/PhysRevMaterials.5.094406
M3 - Article
AN - SCOPUS:85115128918
VL - 5
JO - Physical Review Materials
JF - Physical Review Materials
SN - 2475-9953
IS - 9
M1 - 094406
ER -