Effect of rare-earth (La and Eu) doping on ferroelectric and magnetic properties of magnetoelectric Pb(Fe_(0.5)Nb_(0.5))O_3

摘要

Polycrystalline Pb(Fe_(0.5)Nb_(0.5))O_3 (PFN) samples have been synthesized to study the effect of rare-earth ions, La and Eu, on multiferroic physical properties. The synthesis of materials in controlled PbO atmosphere accounted for the pyrochlore free ceramics with tetragonal structure. Small amount (1 at.%) of rare-earth doping resulted in a shrinkage of unit cell volume. The dielectric studies indicated a decrease in phase transition temperature from 375 K to 356 K for La doped ceramics. A well-saturated ferroelectric polarization with a remanent polarization of 8.9 μC/cm~2 was observed for undoped PFN while the doping affected in the large leakage current and higher coercivity. We observed no significant effect of doping on magnetic transition temperatures at low temperatures. Doping with La resulted in reduced magnetoelectric coefficient compared to the undoped value of 9.2mV/cmOe, due to the poor poling ability.