Microstructure and phase control in Bi-Fe-O multiferroic nanocomposite thin films

作者：Murakami M^*; Fujino S; Lim SH; Salamanca Riba LG; Wuttig M; Takeuchi I; Varughese B; Sugaya H; Hasegawa T; Lofland SE

来源：Applied Physics Letters, 2006, 88(11): 112505.

DOI：10.1063/1.2184892

We report on the controlled multiphase thin film growth in the Bi-Fe-O system. By varying the deposition oxygen pressure, the dominant phase formed in the film continuously changes from ferroelectric BiFeO3 to a mixture of alpha-Fe2O3 and ferromagnetic gamma-Fe2O3. X-ray diffraction and high-resolution transmission electron microscopy have revealed that epitaxial multiferroic nanocomposites consisting of BiFeO3 and Fe2O3 are formed when the deposition pressure is approximate to 5 mTorr. In order to investigate the previously reported anomalous enhancement in magnetization in BiFeO3, we have fabricated a thickness gradient pure BiFeO3 film. The out-of-plane lattice constant was found to increase continuously as the thickness is decreased from 300 to 5 nm, but no significant enhancement in magnetization was observed.

• 出版日期2006-3-13