Modulated crystal structure of Ca5Nb4TiO17 determined using the superspace approach

• Main Authors: Guevarra, Jonathan, van Smaalen, Sander, Schönleber, A., Lichtenberg, Frank
• Format: text
• Published: Animo Repository 2005
• Subjects: Perovskite (Mineral)—Structure; Crystals; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/6455
• Institution: De La Salle University

The superspace approach has been employed to describe the crystal structure of a layered perovskite-related compound Ca5Nb4TiO17. The crystal structure at room temperature has been determined by means of single-crystal x-ray diffraction. The crystal structure is interpreted as a commensurately modulated structure consisting of atomic functions. Structure refinements in (3+1)-dimensional space have validated the efficiency of the superspace approach. Refined atomic site occupancies of Ti4+ show that Ti4+ ions preferentially occupy the central sites over the border sites of the octahedral slabs. Computed valences indicate that Nb and Ti are equally well accommodated by the different octahedral environments in the slabs.