Strong magnetoelastic coupling in Mn3X (X=Ge, Sn)
We measure the full elastic tensors of Mn3Ge and Mn3Sn as a function of temperature through their respective antiferromagnetic phase transitions. Large discontinuities in the bulk moduli at the NÃ©el transitions indicate strong magnetoelastic coupling in both compounds. Strikingly, the discontinuities are nearly a factor of 10 larger in Mn3Ge than in Mn3Sn. We use the magnitudes of the discontinuities to calculate the pressure derivatives of the NÃ©el temperature, which are 39 K/GPa 14.3 K/GPa for Mn3Ge and Mn3Sn, respectively. We measured the in-plane shear modulus c66, which couples strongly to the magnetic order, in magnetic fields up to 18 T and found quantitatively similar behavior in both compounds. Recent measurements have demonstrated strong piezomagnetism in Mn3Sn: Our results suggest that Mn3Ge may be an even better candidate for this effect. Â© 2022 American Physical Society.