Title :
Ferroelectric and magnetic properties of multiferroic BiFeO3-based composite films
Author :
Naganuma, Hiroshi ; Okubo, Tomosato ; Kamishima, Kenji ; Kakizaki, Koichi ; Hiratsuka, Nobuyuki ; Okamura, Soichiro
Author_Institution :
Dept. of Appl. Phys., Tokyo Univ. of Sci., Tokyo
fDate :
5/1/2008 12:00:00 AM
Abstract :
BiFeO3-based composite films were fabricated onto the Pt/Ti/SiO2/Si(100) substrates by a chemical solution deposition (CSD) method using the precursor solutions with various excess iron composition followed by annealing at 923 K for 30 minutes under oxygen gas flow. Coexistence of spontaneous magnetization and remanent polarization could be obtained in the BiFeO2-based composite films with high excess iron composition. The remanent magnetization of almost 20 emu/cm3 and the magnetic coercive field of 1.5 kOe were obtained at the iron composition ratio of Fe/Bi = 1.25. In this specimen, the remanent polarization at 90 K was approximately 10 muC/cm2 at the electric field of 1500 kV/cm. Structural analysis suggested that the remanent polarization has a possibility to increase by suppressing the formation of the secondary phases of Bi2Fe4O9 and alpha-Fe2O3, these are the nonferroelectric material as well as antiferromagnetic phase.
Keywords :
annealing; antiferromagnetic materials; bismuth compounds; coercive force; composite materials; dielectric polarisation; ferroelectric thin films; liquid phase deposition; magnetic thin films; multiferroics; BiFeO3; Pt-Ti-SiO2-Si; annealing; antiferromagnetic phase; chemical solution deposition; ferroelectric properties; magnetic field; magnetic properties; multiferroic composite films; remanent polarization; spontaneous magnetization; structural analysis; temperature 90 K; temperature 923 K; time 30 min; Bismuth; Crystallization; Electric Conductivity; Ferric Compounds; Magnetics; Materials Testing; Membranes, Artificial; Temperature;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2008.755
