%0 Journal Article
%A Lei Bi
%A Alexander R Taussig
%A Hyun-Suk Kim
%A Lei Wang
%A Gerald F Dionne
%A D Bono
%A Kristin A Persson
%A Gerbrand Ceder
%A Caroline A Ross
%B Physical Review B
%D 2008
%G eng
%P 104106
%R 10.1103/PhysRevB.78.104106
%T Structural, magnetic, and optical properties of BiFeO<sub>3</sub> and Bi<sub>2</sub>FeMnO<sub>6</sub> epitaxial thin films: An experimental and first-principles study
%V 78
%8 09/2008
%X <p>BiFeO<sub>3</sub> and Bi<sub>2</sub>FeMnO<sub>6</sub> films were epitaxially grown on SrTiO<sub>3</sub> (001) substrates by pulsed-laser deposition, and their structural, magnetic, magneto-optical and optical properties were measured. In Bi<sub>2</sub>FeMnO<sub>6</sub>, Fe is mainly present in the 3+ valence state, while Mn shows multivalence states. Bi<sub>2</sub>FeMnO<sub>6</sub> exhibits low magnetization at room temperature and at 5 K indicating there is no significant <em>B</em>-site ordering. The BiFeO<sub>3</sub> film shows high optical transparency, while Bi<sub>2</sub>FeMnO<sub>6</sub> shows high absorption loss in the infrared. Density-functional theory modeling of BiFeO<sub>3</sub>, BiMnO<sub>3</sub> and Bi<sub>2</sub>FeMnO<sub>6</sub> was carried out by applying the generalized gradient approximation (GGA) and GGA + <em>U</em> methods. The formation enthalpy of ordered Bi<sub>2</sub>FeMnO<sub>6</sub> is positive for several crystal symmetries and for ferromagnetic (FM) or antiferromagnetic (AFM) spin structures at 0 K temperature, indicating <sub>B</sub>-site ordering is not favored. The electronic structure calculations are consistent with the electronic and optical properties of these films.</p>