Hidden orders and (anti-)magnetoelectric effects in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Cr</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>α</mml:mi><mml:mtext>−</mml:mtext><mml:msub><mml:mi>Fe</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math>

Abstract

$A\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ calculations reveal electric-field-induced local magnetic moments in both Cr${}_{2}$O${}_{3}$ and isostructural Fe${}_{2}$O${}_{3}$. The local responses in Cr${}_{2}$O${}_{3}$ add up to a net magnetoelectric effect, while in Fe${}_{2}$O${}_{3}$ the responses cancel out: an antimagnetoelectric effect. The responses are related to hidden order in the form of ferroically and antiferroically ordered magnetoelectric multipoles.

Topics & Concepts