Novel phase of thin-film iron-doped barium titanate
Date of Award
Doctor of Philosophy (Ph.D.)
First Committee Member
Joshua L. Cohn - Committee Chair
The properties of a new cubic perovskite phase of thin-film BaFe xTi1-xO3 (0.5 ≤ x ≤ 0.75) were studied and compared to those of thin-film BaTiO3 deposited under identical conditions. Cubic perovskite thin-film BaFexTi1-xO 3 (0.5 ≤ x ≤ 0.75) is a novel material because the corresponding bulk compounds have hexagonal structure for comparable x.Lattice constants, electrical resistivity and capacitance, measured as functions of temperature, reveal both in BFTO and BTO a diffuse ferroelectric-parelectric phase transition. It occurs between 200°C and 320°C upon heating, but its signature in structural and electrical properties is suppressed upon cooling. Current vs voltage measurements show that conduction is n-type in BTO and p-type in BFTO. Iron doping also brings about ferrimagnetic ordering, with a Curie temperature above 500°C. Interface properties of capacitors made from BTO and BFTO are also discussed.
Physics, Condensed Matter
Maier, Roland, "Novel phase of thin-film iron-doped barium titanate" (2002). Dissertations from ProQuest. 1834.