In this study, Es80Tp20-Cpxss have been investigated by using X-ray and TOF neutron Rietveld methods to determine site occupancies of Fe3+ and Ti4+ at the octahedral and tetrahedral sites.Es80Tp20-Cpxss was synthesized from oxide mixture at 1240ºC in air for 45 days.X-ray powder data was collected using a RIGAKU RINT automated Bragg-Brentano diffractometer system.A time-of-flight (TOF) powder diffractometer, VEGA, has been operated at the KENS pulsed spallation neutron source. The site occupancies of Fe, Ti and Al at the M1 and T sites, refined by the neutron diffraction data, give following atomic contents at the M1 and T sites: (Fe0.447Al0.554)M1(Al0.646Fe0.354Ti0.200Si0.800)T. Thus, the distribution of Ti in the Es-Tp Cpxss is very different from that expected from ionic radius.
