Structural variation, magnetism and single-source deposition of lanthanide-containing polyoxotitanates

Abstract

Heterometal-containing polyoxotitanates (POTs) are much-studied single-source precursors (SSPs) for doped TiO₂. In this work the properties of a wide range of lanthanide-containing POTs are studied to assess their potential use as SSPs for Ln–Ti hybrid oxides. The novel cage compounds [{Ti₂O(OEt)₈}(EtOH·LnCl)]₂ (Ln = Sm, Gd, Tb, Dy, Ho, Tm and Yb) are structurally characterised. The magnetic properties of the Ln = Dy and Ho compounds were characterised using SQUID magnetometry—in both cases, there is evidence of significant uniaxial magnetic anisotropy, but magnetic relaxation is fast and therefore no single-molecule magnetic properties are observed. Upon decomposition lanthanide-doped anatase (Ln = La) or titania/LnTi–oxide mixtures are obtained, which show efficient stabilisation of the catalytically active anatase phase up to high temperatures, making the materials of potential interest for applications in photocatalysis.