Ballistic Magnetoresitance over 4000% at Room Temperature in Ni-Ni   Electrodeposited Nanocontacts
  This paper reports ballistic magnetoresistance values over 4000% measured in electrodeposited Ni-Ni nanocontacts with T geometry previously developed . Over the time, after several magnetic field cycles, the ballistic magnetoresistance relaxed to a 400%. While that the magnetoreistance of a contact could rise indefinitely; relaxtion and reproducibility are, however, the main issue. We find that the tip ending radius conforming the contacts appears not to play the main role. 
Hai Wang, H. Cheng and N. Garcia