Enhanced magnetoresistance in half-metallic CrO2-TiO2 composites

► CrO2-TiO2 composites consist of large rod-like CrO2 crystals and TiO2 nanoparticles. ► The composites show enhanced magnetoresistance than that of pure CrO2. ► TiO2 in composites acts as grain boundary barrier for spin-dependent tunneling. ► The tunneling mechanism is best described by fluctuation-induced tunneling model.