A Reduced Neodymium Titanate with a New Intergrowth Structure Type

✍ Scribed by B. Hessen; S.A. Sunshine; T. Siegrist; R.B. Van Dover

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 217 KB
• Volume: 105
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1993.1198

✦ Synopsis

Single crystals of a new reduced neodymium titanate, (\mathrm{Nd}{3} \mathrm{Ti}{4} \mathrm{O}{12}), have been obtained by slow cooling of a reduced (\mathrm{Nd}-\mathrm{Ti}-\mathrm{O}) ceramic precursor in a molten neodymium borate flux under high vacuum. Single crystal X-ray diffraction (space group (P \mathrm{cmn}, a=5.420(1) \AA, b=7.610(1) \AA, c=22.015(5) \AA), (Z=4), Pearson symbol oP76) showed that the structure of (\mathrm{Nd}{3} \mathrm{~T}{4} \mathrm{O}{12}) is built from an arrangement of corner-sharing and edge-sharing (\mathrm{TiO}{6})-octahedra that can be considered as a regular intergrowth of the (\mathrm{GdFeO}{3}) and (\mathrm{CaTa}{2} \mathrm{O}{6}) structure types. The material is nonmetallic (\left(R\left(25^{\circ} \mathrm{C}\right)=35 \Omega \mathrm{cm}\right)) which may arise due to the localization of the (\mathrm{Ti} 3 d)-electrons in the edge-sharing pairs of (\mathrm{TiO}_{6})-octahedra (short Ti-Ti distance of 2.760(3) (\AA) ). 1993 Academic Press, Inc.