Effect of dilution of both A- and B- sites on the multiferroic   properties of spinal Mott insulators
  The structural, magnetic, electrical and transport properties of FeV2O4, by doping Li and Cr ions respectively in A and B sites, have been studied. Dilution of A-site by Li doping increases the ferri-magnetic ordering temperature and decreases the ferroelectric transition temperature. This also decreases the V-V distances which in effect increases the A-V coupling. This increased A-V coupling dominates over the decrease in A-V coupling due to doping of non-magnetic Li. On the other hand, Cr doping increases the ferri-magnetic ordering temperature but does not alter the ferroelectric transition temperature which is due to the fact that the polarization origin to the presence of almost non-substituted regions. 
Prashant Shahi (1), R. Singh (1), Shiv Kumar (2), A.Tiwari (4),   A.Tripathi (4), J. Saha (5), S. Patnaik (5), A. K. Ghosh (...
cond-mat.str-el