  Ferroelectric and magnetic properties of Fe-doped K0.45Na0.49Li0.06NbO3
(KNLN) and Cu-doped KNLN ceramics were investigated. Comparing with pure KNLN
ceramic, Fe-doped KNLN shows ferromagnetic and ferroelectric properties
simultaneously while Cu-doped KNLN shows stronger diamagnetic and ferroelectric
properties. The magnetic property in KNLN matrix are believed to be induced by
point defects. The ferromagnetism of Fe-doped KNLN can be explained by the
F-center exchange mechanism, while the antiferroelectric-like loop and
diamagnetism of Cu-doped KNLN was explained by the special defect structure and
Cu1+ ion at A site.
