Strain-induced antiferromagnetic domain switching via the spin Jahn-Teller effect

The spin Jahn-Teller effect, where a degeneracy of magnetic ground states is spontaneously lifted by structural distortions, lends itself to exploitation by the implied magnetoelastic coupling. <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi>CoTi</a:mi><a:mn>2</a:mn></a:msub><a:msub><a:mi mathvariant="normal">O</a:mi><a:mn>5</a:mn></a:msub></a:mrow></a:math> hosts a frustrated topology of magnetic interactions that could realize such coupling, since the observed magnetic ground state requires a spontaneous monoclinic distortion of the crystal. Using resonant elastic x-ray scattering to simultaneously probe the magnetic structure and lattice distortion of <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:msub><c:mi>CoTi</c:mi><c:mn>2</c:mn></c:msub><c:msub><c:mi mathvariant="normal">O</c:mi><c:mn>5</c:mn></c:msub></c:mrow></c:math>, we demonstrate near complete magnetic domain switching by an applied uniaxial stress that is conjugate to the monoclinic strain. Our results, supported by density functional theory calculations, confirm that <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mrow><e:msub><e:mi>CoTi</e:mi><e:mn>2</e:mn></e:msub><e:msub><e:mi mathvariant="normal">O</e:mi><e:mn>5</e:mn></e:msub></e:mrow></e:math> displays spin Jahn-Teller effects that can be understood in terms of modulated Heisenberg exchange interactions, and demonstrate the potential functionality of spin Jahn-Teller materials in spintronic devices sensitive to uniaxial strain. Published by the American Physical Society 2024