Uniaxial pressure effects in the two-dimensional van der Waals ferromagnet <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>CrI</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>
Jan Arneth, M. Jonak, S. Spachmann, Mahmoud Abdel-Hafiez, Y. O. Kvashnin, R. Klingeler
Abstract
Magnetoelastic coupling and uniaxial pressure dependencies of the ferromagnetic ordering temperature in the quasi-two-dimensional layered van der Waals material ${\mathrm{CrI}}_{3}$ are experimentally studied and quantified by high-resolution dilatometry. Clear anomalies in the thermal expansion coefficients at ${T}_{\mathrm{C}}$ imply positive (negative) pressure dependencies $\ensuremath{\partial}{T}_{\mathrm{C}}/\ensuremath{\partial}{p}_{i}$ for pressure applied along (perpendicular to) the $c$ axis. The experimental results are backed up by numerical studies showing that the dominant, intralayer magnetic coupling increases upon compression along the $c$ direction and decreases with negative in-plane strain. In contrast, interlayer exchange is shown to initially increase and subsequently decrease upon the application of both out-of-plane and in-plane compression.