CONCERNING THE RESISTIVITY ANOMALY IN THE LAYERED PNICTIDE OXIDE NA2TI2SB2O

The origin of the resistivity anomaly at 120 K in the layered pnictide oxide Na2Ti2Sb2O is discussed on the basis of tight-binding band stru cture calculations. The Fermi surface of this material is shown to res ult from the superposition of a two-dimensional and four pseudo-one-di mensional components. It is proposed that the resistivity anomaly is a ssociated with a Fermi surface instability of these pseudo-one-dimensi onal portions leading to a periodic lattice distortion.