Nd4Ti9O24: Präparation und Struktur

Preparation and Crystal Structure of Nd₄Ti₉O₂₄ The compound Nd₄Ti₉O₂₄ was prepared by heating mixtures of Nd₂O₃/TiO₂ (1 : 4.5) at temperatures of T = 1 330°C in air (2× 1d). Single crystals of Nd₄Ti₉O₂₄ were obtained by chemical transport reaction (T₂→T₁; T₁ = 1000°C, T₁ = 900°C, 14 d) using chlorine (p(Cl₂, 298 K) = 1 atm) as transport agent with Nd₄Ti₉O₂₄ as starting material. Nd₄Ti₉O₂₄ crystallizes in the orthorhombic space group Fddd (No. 70) with a = 13.9926(11) Å, b = 35.2844(21) Å, c = 14.4676(17) Å (Z = 16). The structure was refined to give R = 4.0% and R, = 3.7%. Main building units are TiO₆ octahedra, NdO₆ distorted square antiprisms and NdO₆ octahedra.