MAGNETORESISTANCE OF KONDO LATTICES

Magnetoresistance at 0 K is theoretically examined. Because Kondo temperatures must be very sensitive to local disorder of ligands around f ions as implied by their large Gr̈neisen constant, they can be random in the neighborhood of defects and dislocations. The disorder of Kondo temperatures gives positive magnetoresistance at low fields, but negative magnetoresistance at high fields; the magnetoresistance has a peak, when the magnetization is about a half of its saturated value. If Kondo temperatures are distributed down to the zero energy, the magnetoresistance can be positively linear to fields at low fields. © 1990 The American Physical Society.