W. Choe et al., Making and breaking covalent bonds across the magnetic transition in the giant magnetocaloric material Gd-5(Si2Ge2), PHYS REV L, 84(20), 2000, pp. 4617-4620
A temperature-dependent, single crystal x-ray diffraction study of the gian
t magnetocaloric material, Gd-5(Si2Ge2), across its Curie temperature (276
K) reveals that the simultaneous orthorhombic to monoclinic transition occu
rs by a shear mechanism in which the (Si, Ge)-(Si, Ge) dimers that are rich
er in Ge increase their distances by 0.859(3) if and lead to twinning. The
structural transition changes the electronic structure, and provides an ato
mic-level model for the change in magnetic behavior with temperature in the
Gd-5(SixGe1-x)(4).