Strong effects of uniaxial pressure and short-range correlations 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>Ge</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mn>6</mml:mn></mml:msub></mml:mrow></mml:math>
S. Spachmann, A. Elghandour, S. Selter, B. Büchner, Saicharan Aswartham, R. Klingeler
Abstract
Cr 2 Ge 2 Te 6 is a quasi-two-dimensional semiconducting van der Waals ferromagnet down to the bilayer with great potential for technological applications. Engineering the critical temperature to achieve room-temperature applications is one of the critical next steps on this path. Here, we report high-resolution capacitance dilatometry studies on Cr 2 Ge 2 Te 6 single crystals which directly prove significant magnetoelastic coupling and provide quantitative values of the large uniaxial pressure effects on long-range magnetic order (T C / p c = 24.7 K/GPa and T C / p ab = -15.6 K/GPa) derived from thermodynamic relations. Moderate in-plane strain is thus sufficient to strongly enhance ferromagnetism in Cr 2 Ge 2 Te 6 up to room temperature. Moreover, unambiguous signs of short-range magnetic order up to 200 K are found.