tailieunhanh - Crystal Structure and Magnetic Properties for Bi1-xEuxFeO3 Compounds

In this study, crystal structure and magnetic properties for Bi1-xEuxFeO3 compounds are presented. When the Eu content was below 5% (x < ), no significant improvement in magnetic properties was observed. However, when x < , ferromagnetism was induced. More particularly, at x = , the compounds experienced a drastically structural transition that governs also their optical properties. | VNU Journal of Science: Mathematics – Physics, Vol. 33, No. 1 (2017) 35-40 Crystal Structure and Magnetic Properties for Bi1-xEuxFeO3 Compounds Ngo Thu Huong1,2,*, Luu Hoang Anh Thu1, Nguyen Ngoc Long1, Nguyen Hoa Hong2 1 Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam Nanomagnetism Laboratory, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea 2 Received 25 January 2017 Revised 18 February 2017; Accepted 20 March 2017 Abstract: BiFeO3 (BFO) is a promising multiferroic material due to its high ferroelectric and antiferromagnetic ordering temperatures. Substituting partially Bi by Rare-Earth (RE) seem to be one way to enhance magnetization of BFO. In this study, crystal structure and magnetic properties for Bi1-xEuxFeO3 compounds are presented. When the Eu content was below 5% (x < ), no significant improvement in magnetic properties was observed. However, when x < , ferromagnetism was induced. More particularly, at x = , the compounds experienced a drastically structural transition that governs also their optical properties. Keywords: BiFeO3; Rare-Earth-doping; Magnetic property; Raman. 1. Introduction BiFeO3 (BFO) is a promising multiferroic material because of its high ferroelectric (about 1100 K) and antiferromagnetic (about 650 K) ordering temperatures, much above room temperature. There are many reports on the magnetization enhancement of BiFeO3 bulks, thin films, and nanoparticles, due to Bi-site substitution by selected trivalent rare-earth and divalent ions, or Fe-site substitution by transition metal ions. Liu et al. [1] suggested that the reason for higher magnetization after substitution of Eu3+ is the presence of the rare-earth orthoferrite impurity phase. Additionally, in certain cases, as reported by Qian et al. [2] for Dy3+ substitution, there is a large decrease in the particle size after substitution and this could be the reason for increased .