Magnetoelastic interactions in SrCu2(BO3)2 studied by Raman scattering experiments and first principles calculations

Dynamic and static crystal lattice properties of SrCu2(BO3)2 are studied by means of Raman scattering, magnetostriction, and thermal expansion measurements in magnetic fields to 45 T. Raman experiments versus temperature reveal that some phonon modes show an unusual behavior: their frequencies soften (modes at 200 and 450 cm−1) while others harden (modes at 385 and 478 cm−1) when decreasing the temperature below 15 K. Magneto-Raman experiments …