Local structure characterization of superconducting MgCNi3 prepared by SHS technique

Extended X-ray absorption fine structure measurements at the Ni K absorption edge on MgCNi3 prepared by an alternative method based on the self-propagating high-temperature synthesis (SHS) technique are reported in the temperature range from 5 up to 300 K. The temperature dependence of the interatomic Ni-Ni and Ni-Mg distances is in agreement with the values reported for samples obtained by the common solid state route, which has been largely used up to now. The Ni-Ni and Ni-Mg Debye-Waller factors can be well described by a correlated Debye model, with theta(D) = 287 K. The present measurements confirm the good quality of the samples produced by the SHS method. (c) 2007 Elsevier B.V. All rights reserved.