Electrical and magnetic properties of the two crystallographic forms of BaRuO3

We report the results of magnetic susceptibility and electrical resistivity measurements on single crystals of the nine-layer and four-layer crystallo graphic forms of BaRuO3. The two forms differ in the relative amounts of co rner and face sharing of RuO6 octahedra. They display qualitatively differe nt properties below approximately 100 K: the four-layer form shows a metall ic resistivity down to low temperatures, while the nine-layer shows a cross over to a more resistive state. No local moment magnetism is observed in ei ther phase below 400 K, which is of particular interest in the context of p reviously observed magnetic and superconducting phases in the Sr-Ru-O syste m. Resistive measurements to temperatures below 0.1 K reveal no occurrence of superconductivity in either form. [S0163-1829(99)09307-8].