UNUSUAL MAGNETIC PROPERTIES OF RARE-EARTH TITANIUM OXIDES RTiO3: EFFECT OF THE RARE EARTH ON THE MAGNETIC MOMENT OF TITANIUM IN LaxY1 - xTiO3 AND GdTiO3.

The rare-earth orthotitanites, RTiO//3, are a relatively new series of materials with properties quite different from those of the isostructural orthoferrites (RFeO//3), orthochromites (RCrO//3) and orthovanadites (RVO//3). The properties of these materials are strongly dependent on the idenitity of the rare-earth ion. For example, LaTiO//3 is metallic and Pauli paramagnetic, while YTiO//3 is ferromagnetic (T//c equals 29 K) and semiconducting. Low-temperature magnetization studies on the system La//xY//1// minus //xTiO//3 and the compound GdTiO//3 indicate that the magnitude of the Ti**3** plus spontaneous moment depends on the average size of the rare-earth ion and on its magnetic moment. For most of the phases studied except GdTiO//3 the Ti**3** plus moment is very much smaller than the 'spin only' value and is non-integral, yet semiconducting behavior is simultaneously observed.