TITANIUM-III WARWICKITES - A FAMILY OF ONE-DIMENSIONAL DISORDERED MAGNETIC SYSTEMS

We present x-ray, susceptibility, and magnetization (up to 18 T) measurements in the compound MgTiOBO3, which forms in the structure known as warwickite. This structure is characterized by the presence of ribbons along the c axis where the metallic ions are located. This system is magnetic since the Ti ions are in the valence state Ti3+ with the electronic configuration 3d1. Its susceptibility has a temperature dependence, at low temperatures, given by χ(T) T-α, with the exponent α0.83. The low-temperature behavior of the magnetization, as a function of field, is described by m Hγ with γ1-α. These results, together with the x-ray measurements, allow us to identify this material as belonging to a family of inorganic, one-dimensional, disordered magnetic systems. © 1994 The American Physical Society.