Growth and characterization of novel Ir1–xCrxO2 thin films

Novel Ir1–xCrxO2 thin films have been prepared by reactive co–sputtering deposition. Composition, structure and electric and magnetic behavior have been analyzed by different techniques including EDX, XRR, XRD, SQUID magnetometry, electrical resistivity and XANES and XMCD spectroscopies. Despite the difficulty in growing CrO2 by physical deposition techniques, an Ir1–xCrxO2 solid solution phase could be achieved for 0 ≤ x ≤ 0.8, where the oxidation state of Cr is found to remain as 4+. Both the electrical and the magnetic behavior are shown to starkly depart from those of the parent IrO2 (paramagnetic metal) and CrO2 (half–metal ferromagnet) compounds. In particular, they show a semiconducting behavior, dρ/dT