Powder magnetoresistance of Co₂Cr_0.6Fe _0.4Al/Al₂O₃ powder compacts

Abstract

We report on the magnetotransport properties of Co2 Cr0.6 Fe0.4 Al mixed with insulating Al2 O3. The powder compacts show a maximum magnetoresistance of 88% at a saturation moment of 0.125 T at 295 K. Different explanations for the reversible mechanism will be discussed, such as tunneling between contiguous ferromagnetic grains, particle movement, and magnetostriction. The effect in Co2 Cr0.6 Fe0.4 Al Al2 O3 powder compacts is the largest room temperature magnetoresistance that has been measured until now. © 2006 American Institute of Physics.