Magnetic and electric properties of Sr FeMoO

We present electrical resistivity () and magnetic susceptibility () data of the Sr FeMoO double perovskite. We found that the as prepared sample shows semiconducting (¹) in the whole temperature range and a magnetoresistance behavior typical of electron tunneling at the grain boundaries (gb). When the oxygen of the gb is removed drops one order of magnitude. Below the magnetic ordering temperature ¹ +405 K and above 590 K this sample is metallic (d/d¹'0), while for ¹ (¹(590 K we observe a weak localization. The(¹) data follow the Curie}Weiss law only in a short temperature range above ¹ . 2001 Elsevier Science B.V. All rights reserved.