Precise measurement of the lattice spacing of LaB6 standard powder by the x-ray extended range technique using synchrotron radiation

We used the basis of the x-ray extended range technique to measure the lattice spacing of LaB6 standard powder samples relative to silicon 640b standard powder samples with an accuracy of 5310−5 Å. Measurements were not constrained to one energy but were carried out over a 5 keV–20 keV energy range. These measurements used powder diffraction to determine the synchrotron beam energy, to diagnose discrepancies in the nominal calibrated beam energies, and to determine beam energy bandwidths as a function of energy. More specifically, this technique is able to yield a result independent of certain energy-dependent systematics and to yield the most accurate determination of the lattice spacing of NIST SRM 660 LaB6 standard powder so far undertaken. This has direct application to beam line energy calibration, structural evaluation, edge energy calibration, and lattice spacing determinations.