Dielectric and Structural Properties of Bi5Ti3FeO15 Ceramics Obtained by Solid-State Reaction Process from Mechanically Activated Precursors

Abstract

Bi 5 Ti 3 FeO 15 (BTFO), an Aurivillius compound, was synthesized via sintering the Bi 2 O 3 and Fe 2 O 3 mixture and TiO 2 oxides. The precursor material was ground in a high-energy attritorial mill for (1, 3, 5, and 10) h. The orthorhombic system Bi 5 Ti 3 FeO 15 ceramics was obtained by a solid-state reaction process at 1313 K. Phase formation behavior was investigated using differential thermal analysis (DTA), thermal gravimetric (TG), and X-ray diffraction (XRD) techniques. The frequencydependent properties of the material were investigated by impedance spectroscopy. The impedance spectroscopic method is widely used to characterize electrical properties of materials and their interfaces with electronically conducting electrodes. These studies indicate that 1h, 3h, and 5h primary high-energy ball milling followed by sintering is a promising technique for pure Bi 5 Ti 3 FeO 15 ceramic preparation, whereas the ceramics obtained from the substrates after 10h milling is a two-phase material. As the result of this investigation, the model of adjusting the Nyquist charts with a three-element R-CPE (constant phase element) series connection was proposed. It was found that the value of the dielectric constant at the Curie temperature decreases when the milling time of the substrates increases. The decrease in the dielectric constant is influenced by the great dispersion of the grains, their dense packing, and location of particular grains in relation to other grains. Moreover, the change of resistivity with frequency indicates that relaxation processes take place in the material. In conclusion, J. Dercz (B)

Archives of Metallurgy and Materials

“…The Curie temperature for pure Bi 5 Ti 3 Feo 15 ceramics is equal 759ºC and corresponding to a structural transition from the ferroelectric phase A21am to paraelectric phase i4/mmm [13]. The same value of Curie temperature has been obtained by other authors [14,15]. in the opinion of the hereby paper the observed broadened peaks corresponds to the space charge polarization, as has been suggested by tha authors of following paper [14].…”

Effect of High Energy Ball Milling on the Structure and Phase Decomposition of the Multiferroic Bi5Ti3FeO15Ceramics

“…Among the smart materials, ferroics, biferroics, and multiferroics are of high importance. They are characterized by unique physical properties [3][4][5][6][7][8][9][10]. In 1994 Schmid as multiferroics called the materials which simultaneously displayed at least two ferroic states [11].…”

“…During the HEBM process, the surface activity of the milled powders is enhanced due to the crash and shock, and -after milling -the surface activity of powders is in the metastable high-energy state. Fine dispersion powders obtained in this way may be used in the synthesis of ceramics with high density as well as to obtain thin film multilayered systems [3,4,7].…”

“…Experimental details As a starting material for milling, multiferroic single phase ceramics with the composition of BTF (ICDD PDF 82-0063) obtained by a solid state reaction process from mechanically activated precursors was used [7]. The pellets obtained in this way, within the framework of this study, were subjected to high-energy ball milling in the Fritch PULVERISETTE 7 premium line ball mill.…”

Rietveld Analysis of Aurivillius-Type Structure Ceramics Synthesized from Precursors Prepared by Classical and HEBM Methods

“…Sites A are occupied by large cations (e.g. Ba, Sr, Ca, Bi, Pb), positions B are filled by small cations of transition metals (Ti, Nb, Ta, Mo, W, Fe, Mn), and m is the number of oxygen regular octahedrons arranged layer by layer, along the z axis of the perovskite package (m = 1, 2, 3, 4, 5, 8) [8][9][10][11][12][13][14][15]. Compounds with the layered perovskite-like structure include such materials as a bismuth titanate (Bi 4 Ti 3 O 12 , m = 3).…”