Commensurate Nb₂Zr₅O₁₅: Accessible Within the Field Nb₂Zr_xO_2x+5 After All

Abstract

Doped niobium zirconium oxides are applied in field‐effect transistors and as special‐purpose coatings. Whereas their material properties are sufficiently known, their crystal structures remain widely uncharacterized. Herein, we report on the comparably mild sol‐gel synthesis of Nb2Zr5O15 and the elucidation of its commensurately modulated structure via neutron diffraction. We describe the structure using the most appropriate superspace as well as the convenient supercell approach. It is part of an α‐PbO2‐homeotypic field with the formula Nb2ZrxO2x+5, which has previously been reported only for x≥5.1, and is closely related to the structure of Hf3Ta2O11. The results, supported by X‐ray diffraction and additional synthesis experiments, are contextualized within the existing literature. Via the sol‐gel route, metastable Nb−Zr−O compounds and their heavier congeners are accessible that shed light on possible structures of these commercially utilized materials.

Charge Transport in the A6B2O17 (A = Zr, Hf; B = Nb, Ta) Superstructure Series

“…For example, A 4 B 2 O 13 and A 8 B 2 O 21 compounds were synthesised. 10,11 Others have also identified similar structures such as Zr x-2 Nb 2 O 2x+1 , 10 Zr 5 Nb 2 O 15 , 12 Hf 3 Ta 2 O 11 , Hf 5 Ta 2 O 15 and Hf 7 Ta 2 O 17 . 13 All these structures are very similar and, in most cases, can only be distinguished by the change in the oxygen sublattice.…”