Significant ferrimagnetism observed in Aurivillius Bi_4Ti_30_(12) doped by antiferromagnetic LaFeO_3

摘要

Highly crystalline quality c-axis epitaxial nLaFe0_3-Bi_ 4Ti_30_(12) (n=0.5,1.0,1.5) thin films were deposited on SrTiO_3 (001) substrates by pulsed laser deposition. The x-ray diffraction and transmission electron microscopy characterizations confirm that there are designed even-odd number perovskite-block structures in n=0.5 and 1.5 films while it has even-even number ones in n=1.0 films. The remarkable physical property of n=0.5 and 1.5 samples is the presence of ferrimagnetism even up to room temperature. While it is antiferromagentic property in n=1.0 sample. The observed ferrimagentism is explained qualitatively by considering the crystal structure in nLaFeO_ 3-Bi_4Ti_3O_(12).