Electric-field-induced phase switching in textured Ba-doped bismuth ferrite lead titanate

The template grain growth technique was used to synthesis textured 60BiFeO3-PbTiO3 (60'40BFPT) by using platelets of BaTiO3 as template. Synchrotron measurement clearly showed textured 60'40BFPT. Moreover, in situ high energy synchrotron radiation was employed to investigate the influence of an external electric filed on crystallographic structure of mixed phase 60:40BFPT. Application of an electric field ≥ 1 kV/mm resulted in phase transformation from mixed rhombohedral/tetragonal phases (≈ 73.5% tetragonal / 26.5% rhombohedral) to predominately tetragonal phase (≈ 95%) at applied field of 6 kV/mm

Texture analysis of thick bismuth ferrite lead titanate layers

The template grain growth technique was used to synthesis textured 60BiFeO3-PbTiO3(60:40BFPT) by using platelets of BaTiO3 as template. Synchrotron measurement clearly showed textured 60:40BFPT. Moreover, in situ high energy synchrotron radiation was employed to investigate the influence of an external electric filed on crystallographic structure of mixed phase 60:40BFPT. Application of an electric field ≥ 1 kV/mm resulted in phase transformation from mixed rhombohedral/tetragonal phases (≈ 73.5% tetragonal / 26.5% rhombohedral) to predominately tetragonal phase (≈ 95%) at applied field of 6 kV/mm. A crystallographic texture refinement was done by using software package materials analysis using diffraction (MAUD) with a 4th order spherical harmonic orientation distribution function (ODF). This refinement was completed using a P4mm+Cm structure model. Texture coefficients were constrained such that the equivalent texture coefficients of each phase are the same. The resulting texture refinement determined that sample has a 1.3 multiples of random distribution (MRD) {100} crystallographic texture

USE OF HIGH SURFACE NANOFIBROUS MATERIALS IN MEDICINE

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Crystallographic and magnetic investigations of textured bismuth ferrite lead titanate layers

In present work we demonstrate the synthesis of textured 60BiFeO3–40PbTiO3 (60:40 BFPT) by using the templated grain growth technique with platelets of BaTiO3. Synthesised 60:40 BFPT has been examined by High-energy x-ray diffraction utilizing a synchrotron x-ray source. The crystallographic structure refinement results revealed the co-existence of monoclinic and tetragonal phases. By employing an external electric field, the mixed monoclinic/tetragonal phases transformed to the predominantly tetragonal phase. In addition, a crystallographic texture refinement was completed on unpoled state of 60:40 BFPT which showed the sample had 1.3 multiples of random distribution (MRD) {100} crystallographic textured in tetragonal phase. However, magnetic measurements showed isotropic ferromagnetism for the sample which is not in agreement with the crystallographic texture properties of the sample. Low temperature magnetic transition has been found in zero field cooled—field cooled (ZFC-FC) measurements. This could be due to the possible existence of a secondary magnetic phase, which dominated the magnetic result

Characterization of thick bismuth ferrite-lead titanate films processed by tape casting and templated grain growth

The templated grain growth technique was used to synthesise textured 60BiFeO3–40PbTiO3 (60:40BFPT). Both Aurivillius (Bi4Ti3O12, PbBi4Ti4O15) and perovskite templates (BaTiO3, SrTiO3) were used to prepare 60:40BFPT. Only BaTiO3 templates were found to successful impart a texture to the ceramic matrix. In the case of perovskite templates, ferroelectricity was evident from saturated polarisation hysteresis loops. Saturated polarisation loops were achieved due to the substitution of Ba2+ or Sr2+, which reduces the coercive field. SrTiO3 and BaTiO3 templated ceramics showed remanent polarisation of 30 and 36 μC/cm2, respectively. Aurivillius templates did not generate ferroelectric materials. Because of their high chemical stability in this system, BaTiO3 templates appear to be the best candidate for fabricating textured BFPT by the reactive templated grain growth method