Two channels of the conductance G exist in cold-pressed powder compacts of CrO2/sCrO2/Cr2O3d, where two types of granules have different coercivities. One of the channels is the spin-dependent intergranular tunneling conductance, and the other one is the spin-independent higher-order inelastic hopping conductance. The conductance is mainly related with the spin-dependent tunneling channel at low temperature. A large low field tunneling magnetoresistance sTMRd of 30.4% is achieved in 950 Oe field at 2 K. The reason is the relative orientation of the magnetization that tends to be antiparallel between the two coercivities. Field dependence of the tunneling magnetoresistance shows two better-separated peaks than that of CrO2 powder compact. The results suggest that the introduction of CrO2/Cr2O3 improves low field sensitivity, TMR, and switching characteristics. © 2005 American Institute of Physics.
Wang, Jingping; Che, Ping; Feng, Jing; Lu, Minfeng; Liu, Jianfen; Meng, Jian; Hong, Yuanjia; and Tang, Jinke (2005). "A large low-field tunneling magnetoresistance of CrO 2 / ( CrO 2 ∕ Cr 2 O 3 ) powder compact with two coercivities." JOURNAL OF APPLIED PHYSICS .97, 073907-1-073907-4.