Powder x-ray diffraction of BaFe2As2 under hydrostatic pressure

Abstract

We have performed powder x-ray diffraction study on BaFe2As 2 under hydrostatic pressures up to 6 GPa at room temperature. Hydrostatic pressure was produced by means of a diamond anvil cell with He gas as a pressure transmitting medium. Single crystalline sample of BaFe 2As2 was ground in alumina mortar cooled with liquid nitrogen to produce a fine powder sample. The diffraction patterns show a tetragonal structure with a space group of I4/mmm in the whole pressure range. Rietveld analysis on the experimental results shows that the lattice parameters are monotonically decreased with increasing pressure. The As-Fe-As bond angle does not reach the ideal tetrahedral value of 109.47°. © Published under licence by IOP Publishing Ltd.