SYNTHESIS AND RIETVELD CRYSTAL-STRUCTURE REFINEMENT OF MACKINAWITE, TETRAGONAL FES

Mackinawite, tetragonal FeS, has been synthesised by reacting iron wit h Na2S solutions. A Rietveld structure refinement of X-ray powder diff raction data, recorded using X-rays monochromated from synchrotron rad iation with a wavelength of 0.6023 Angstrom, has been performed. The s tructure has been refined in the tetragonal space group, P4/nmm, and h as the following cell parameters: a = 3.6735(4), c = 5.0328(7) Angstro m, V = 67.914(24) Angstrom(3). Our refinement shows that the FeS4 tetr ahedron in mackinawite is almost perfectly regular, with a much smalle r distortion than has been previously reported. An improved X-ray diff raction data set is provided.