Elastic properties of type-I clathrate K8Zn4Sn42 determined by inelastic X-ray scattering Bogdan M. Leu, Mihai I. Sturza, Jiawang Hong, Ahmet Alatas, Volodymyr Baran and Thomas F. Fässler EPL, 113 1 (2016) 16001 Published online: 26 January 2016 DOI: 10.1209/0295-5075/113/16001