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Effect of Sb and MnO2-Doping on Phase Transitions, Crystal Structure, Thermal, Dielectric, Ferroelectric and Piezoelectric Properties of Na0.5K0.5NbO3 Ceramics

Suchanicz J., Faszczowy I., Czaja P., Kusz J., Zubko M.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 2

633--639

EN

Lead-free ceramics of Na0.5 K0.5 Nb1-x Sbx O3 (NKNS) and Na0.5 K0.5 Nb1-x Sbx O3 + 0.5 mol%MnO2 (NKNS + 0.5 mol%MnO2) (0 < x < 0.06) ceramics were prepared by a conventional solid-state hot pressing method. The ceramics possess a single-phase perovskite structure with orthorhombic symmetry. Microstructural examination revealed that Mn doping of NKNS leads to improvement of densification. The cubic-tetragonal and tetragonal-orthorhombic phase transitions of NKNS shifted to higher and lower temperature, respectively after introduction of Mn ion. Besides, ferroelectric and piezoelectric properties were improved. The results were discussed in term of difference in both ionic size and electronegativity of Nb5+ and Sb5+ and improvement of densification after Mn ion doping.

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Effect of Ba addition on the structural, dielectric and ferroelectric properties of Na0.5Bi0.5TiO3 ceramics

Suchanicz J., Lewczuk R., Konieczny K., Dutkiewicz E. M.

Materials Science Poland

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2015

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Vol. 33, No. 2

414--417

EN

Lead-free (Na0.5Bi0.5)(1-x)BaxTiO3 (x = 0, 0.04 and 0.06) ceramics were fabricated by conventional solid phase sintering process. X-ray diffraction analysis shows that obtained specimens possess the perovskite structure. The microstructure study shows a dense structure, in good agreement with the relative density determined by the Archimedes method (above 95 %). Electric permittivity anomaly is shifted to low temperature after Ba doping of NBT. The pyroelectric and hysteresis loops measurements show that polarization and coercive field increases and decreases, respectively, after Ba doping of NBT. The obtained results are discussed in terms of ions/lattice imperfections, which create local electromechanical fields. The investigated ceramics are considered to be promising candidates for lead-free electronic materials.

3

Fabrication of 0.95BaTiO3-0.05Pb(Mg1/3Nb2/3)O3 ceramics by conventional solid state reaction method

Nogas-Ćwikiel E., Suchanicz J.

Archives of Metallurgy and Materials

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2013

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Vol. 58, iss. 4

1397--1399

EN

The possibility to obtain of ceramic solid solution between barium titanate and lead magnesium niobate by two-step sintering technique through conventional solid-state reaction method has been investigated. In the first step MgNb2O6 has been synthesized. In the second step 0.95BaTiO3-0.05Pb(Mg1/3Nb2/3)O3 has been obtained using MgNb2O6, PbO and BaTiO3. The two-step sintering technique is effective for the synthesized of 0.95BaTiO3-0.05Pb(Mg1/3Nb2/3)O3 ceramics. Single-phase (pyrochlore-free) ceramics with perovskite phase were obtained.

PL

Badano możliwość otrzymania ceramicznego roztworu stałego ty tanianu baru i niobianu ołowiu magnezu metodą reakcji w fazie stałej. Ceramikę otrzymano dwuetapowo. W pierwszym etapie zsyntezowano MgNb2O6. W drugim etapie z 0.95BaTiO3-0.05Pb(Mg1/3Nb2/3)O3 otrzymano 0.95BaTiO3-0.05Pb(Mg1/3Nb2/3)O3. Użyta metoda dwuetapowa okazała się skuteczna dla otrzymania ceramiki 0.95BaTiO3-0.05Pb(Mg1/3Nb2/3)O3. Otrzymano jednofazową ceramikę o strukturze typu perowskitu. bez niepożądanej fazy pirochloru.