Structural transformation and multiferroic properties of single-phase Bi0.89Tb0.11Fe1-xMnxO3 thin films

Pure BiFeO3 (BFO) and Tb, Mn co-doped BiFeO3 (BTFMO) thin films were deposited on SnO2: F (FTO)/glass substrates using a chemical solution deposition method. Detailed investigations were made on the influence of (Tb, Mn) co-doping on the structure change and the electric properties of the BFO films. With the co-doping of Tb and Mn, the structural transformation from rhombohedral R3c to triclinic P1 is confirmed through XRD, Rietveld refinement and Raman analysis. XPS analysis clarifies that (Tb, Mn) co-doping avails to decrease oxygen vacancy concentration, showing less Fe2+ ions in the co-doped BTFMO thin films than that of the pure BFO thin film. Among the co-doped thin films, the BTFM1O film shows the highly enhanced ferroelectric properties with a giant remnant polarization value (2P(r) = 180.3 mu C/cm(2)). The structural transformation, the well-distributed fine grains and the reduction of leakage current favor enhanced ferroelectric property of (Tb, Mn) co-doped BFO films. It is also found that the BTFM1O film shows the enhanced ferromagnetism with the saturated magnetization (M-s = 2.5 emu/cm(3)) as a result of the collapse of space modulated spin structure by the structure transformation. (C) 2013 Elsevier B. V. All rights reserved.