Compositional Tuning of the Aurivillius Phase Material Bi5Ti3−2xFe1+xNbxO15 (0 ≤ x ≤ 0.4) Grown by Chemical Solution Deposition and its Influence on the Structural, Magnetic, and Optical Properties of the Material

摘要

A series of Aurivillius phase materials, Bi5Ti3-2xFe1+xNbxO15 (x = 0 , 0.1, 0.2, 0.3, and 0.4), was fabricated by chemical solution deposition. The effects of aliovalent substitution for the successful inclusion of Fe3+ and Nb5+ by replacing Ti4+ were explored as a potential mechanism for increasing magnetic ion content within the material. The structural, optical, piezoelectric, and magnetic properties of the materials were investigated. It was found that a limit of x = 0.1 was achieved before the appearance of secondary phases as determined by the X-ray diffraction. Absorption in the visible region increased with increasing values of x corresponding to the transition from the valence band to the conduction band of the Fe-e(g) energy level. Piezoresponse force microscopy measurements demonstrated that the lateral piezoelectric response increased with increasing values of x . Magnetic measurements of Bi5Ti2.8Fe1.1Nb0.1O15 exhibited a weak ferromagnetic response at 2, 150, and 300 K of 2.2, 1.6, and 1.5 emu/cm(3) with H-c of similar to 40 , 36, and 34 Oe, respectively. The remanent magnetization M-R of this sample was found to be higher than the range of reported values for the Bi5Ti3Fe1O15 parent phase. Elemental analysis of this sample by energy-dispersive X-ray analysis did not provide any evidence for the presence of iron-rich secondary phases. However, it is noted that a series of measurements at varying sample volumes and instrument resolutions is still required in order to put a defined confidence level on the Bi5Ti2.8Fe1.1Nb0.1O15 material being a single-phase multiferroic.