Giant Inverse Tunneling Magnetoresistance in Single CrO_2 / Vacuum / Ni_80Fe_20 Using Conductive AFM

Abstract

The chromium dioxide (CrO₂) is a half metallic ferromagnet which has both the metallic and semiconductive spin bands.The tunneling magnetoresistance (TMR) has been measured in single CrO₂ deposited on (110) TiO₂/vacuum/ Ni₈₀Fe₂₀ film on the AFM cantilever at room temperature. The behavior showed the giant inverse type of the TMR and the values of the TMR ratio from -74% to -63% were estimated using the experimental results, which means the spin polarization of-100% in CrO₂. It was estimated that the surface of CrO₂ has the insulator layer with the thickness of about 8~10[nm].