Effects of La concentration on the structural and magnetic properties of BiFe03 nanoparticles

摘要

Bi_(1-x)La_xFeO_3 (x= 0.05, 0.1, 0,15, 0.2, and 0.25) nanoparticles were synthesized by sol-gel method, and the effects of La content on the structure and magnetic properties were investigated. X-ray diffraction and Raman analysis showed that the structure of La-doped BiFeO_3 was transformed from a rhombohedral to a orthorhombic with the increase of La content. This was also accompanied by an increase in the magnetization up to x=0.20 followed by a reverse trend at higher doping levels. The enhanced ferromagnetism might be attributed to the antiferromagnetic core and ferromagnetic surface of the nanoparticles, the increasing of canting angle, and the structural distortion. When the dopant concentration up to x=0.25, the decreased ferromagnetism might be attributed to the decreased of ferromagnetic component of canted Fe sublattice.