Structural and magnetic properties of pyrochlore solid solutions (Y,Lu)2Ti2−x(Nb,Ta)xO7±y

The synthesis and characterization of the pyrochlore solid solutions, Y2Ti2−xNbxO7−y, Lu2Ti2−xNbxO7−y, Y2Ti2−xTaxO7−y and Lu2TiTaO7−y (−0.4

Synthesis of pyrochlore solid solutions (Y,Lu)2Ti2−x(Nb,Ta)xO7±y under high vacuum at 1600 °C results in oxygen deficient, paramagnetic compounds with reduced B-site cations. Studies indicate Ti3+ as the source of the localized moments, with no evidence for localized Nb4+ moments. Annealing under O2 results in fully oxidized, oxygen excess pyrochlores as white powders. Powder neutron diffraction studies show the excess oxygen on the normally vacant 8a site.Figure optionsDownload as PowerPoint slide