Naslov
Structural and electrical properties of hydrothermally synthesized barium titanate nanostructures

Autori
Gajović, Andreja ; Plodinec, Milivoj ; Šantić, Ana ; Šipušić, Juraj ; Čeh, Miran

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
COST MP0904: SIMUFER, Closing Conference and Final Management Committee, Book of Abstract / Mitoseriu, Liliana - Genova : Institute of Energetics and Interphases IENI-CNR Genoa, 2014, P21-P21

Skup
COST MP0904: SIMUFER, Closing Conference and Final Management Committee

Mjesto i datum
Genova, Italija, 30.01.2014. - 01.02.2014

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
barium titanate nanostructures; TEM; Raman spectroscopy; phase transition

Sažetak
BaTiO3, is a well-known and widely investigated dielectric material. It is mainly used in capacitors due to its high dielectric constant. The dielectric properties of BaTiO3 are controlled by purity and microstructure which are dependent on the methods of preparation. Recent advances in nanotechnology such as MLCC, MEMS, DRAM have resulted in miniaturization of devices [1, 2]. These require nanosize BaTiO3. Various chemical routes like precipitation, sol-gel, sol precipitation, hydrothermal, reverse miscellar etc. are known to yield nanoparticle products. The sol-precipitation method gives fine particle size, simple compositional control and low processing temperature [3]. Barium titanate is also used for electronic devices in technological ceramic industry because of its ferroelectric, thermoelectric and piezoelectric properties when it assumes the tetragonal structure. As such it has application in production of capacitors, positive temperature coefficient resistors, dynamic random access memories, electromechanics and nonlinear optics [4]. In this work barium titanate nanostructures were synthesized by hydrothermal method from several precursors: TiO2 nanopowder, titanate nanotubes (H2Ti3O7), TiO2 nanotubes and aqua solution of BaCl2 and NaOH. Structural and compositional properties were investigated by XRD, SEM, EDX, TEM, HRTEM, SAED and Raman spectroscopy (ex –situ and in-situ), while electric measurements were studied by impendence spectroscopy. In case of synthesis from TiO2 nanopowder and H2Ti3O7 nanotubes precursors, obtained BaTiO3 nanoparticles were found to be about 50 nm in size, homogenous, and in tetragonal phase. For TiO2 nanotubes precursor we obtained BaTiO3/TiO2 composites with low amount of BaTiO3 tetragonal phase. Tetragonal phase of BFO, having 4mm symmetry with c/a axis ratio close to one, is hard or impossible to distinguish from cubic phase by using diffraction techniques, so the phase purity and the structure were studied by Raman spectroscopy (RS) as a main technique [5]. The purity of the samples depends on the synthesis procedure. In situ low and high temperature RS was used for study of ferroelectric phase transitions from tetragonal to cubic phase. The electrical conductivity and dielectric constant will be discussed in the relation to RS measurements.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

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