Dresden 2011 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 36: SC: Fe-based Superconductors - 122 - Properties, Electronic Structure, Mechanisms

TT 36.6: Vortrag

Mittwoch, 16. März 2011, 15:15–15:30, HSZ 304

Tetragonal lattice collapse in SrFe₂As₂ - a combined experimental and theoretical study — •Miriam Schmitt¹, Deepa Kasinathan¹, Alim Omerci¹, Katrin Meier¹, Ulrich Schwarz¹, Michael Hanfland², Klaus Koepernik³, Yuri Grin¹, Andreas Leithe-Jasper¹, and Helge Rosner¹ — ¹MPI CPfS, Dresden, Germany — ²ESRF, Grenoble, France — ³IFW, Dresden, Germany

In a joint experimental and theoretical study we investigate the crystal structure of the Fe pnictide compounds SrFe₂As₂ under applied hydrostatic pressure. Applying high pressure X-ray diffraction, for a critical pressure of about 10 GPa we observe a sudden collapse of the tetragonal c axis, accompanied by a small expansion of the basal plane. This results in a drastic reduction of the c/a ratio and a significant decrease of the unit cell volume. This tetragonal collapse is well described by DFT band structure calculations and can be assigned to the formation of an additional As-As bond along the tetragonal c axis.