Effect of Ti on the properties of (KxNa1−x)NbO3 based lead-free ceramics

Mgbemere, Henry E.; Schneider, Gerold A.

doi:10.1016/j.ceramint.2015.07.101

Cited by 3 publications

(3 citation statements)

References 30 publications

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“…The observed and calculated intensity profiles are well matched, which is confirmed by their difference profiles, shown at the bottom of each figure; the smoother solid line indicates the more accurate results. The low-reliability factor value R wp (8.3-8.8%) and the goodness-of-fit indicator S close to 1 (Table 1) suggest the high degree of reliability of the refinement results; a comparison with values reported from other studies [19][20][21][22] also proved the high reliability of our results. In the Rietveld analysis results, the constituent phases and their volume fractions are presented as a function of x and y, as shown in Figure 3.…”

Section: Resultssupporting

confidence: 75%

Co-Doping Effect of BiGaO3 and (Bi,Na,K,Li)ZrO3 on Multi-Phase Structure and Piezoelectric Properties of (K,Na)NbO3 Lead-Free Ceramics

Lee

2019

Energies

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The phase boundary structure of (K,Na)NbO3 piezoelectric ceramic was modified by doping with Bi(Na,K,Li)ZrO3 and BiGaO3 through normal solid-state sintering. Rietveld refinements by X-ray diffraction revealed that the Bi(Na,K,Li)ZrO3/BiGaO3 co-doping in (K,Na)NbO3 led to a multi-phase structure at room-temperature, effectively moving the rhombohedral-orthorhombic (R-O) and orthorhombic-tetragonal (O-T) polymorphic phase transition temperatures close to the room temperature region. Increased levels of doping also generated a structural transition, i.e., triphasic R-O-T to diphasic R-T (T-rich) and finally to R-T (R-rich), contributing to shrinkage of the O phase as well as the increase of R phase fraction. A sensitive influence of the BiGaO3 doping (0.001 mole fraction level) on the structural properties such as the phase and microstructure was shown, resulting from the effect of the super-tetragonal structure of BiGaO3. The d33 property was strongly dependent on the phase and its volume fraction, in addition to the grain sizes. Eventually, enhanced and balanced properties of the piezoelectric coefficient and Curie temperature (d33 = 309 pC/N, TC = 343 °C) were obtained when the doped ceramic had a T-rich (86%) R-T structure.

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Section: Resultssupporting

confidence: 75%

Co-Doping Effect of BiGaO3 and (Bi,Na,K,Li)ZrO3 on Multi-Phase Structure and Piezoelectric Properties of (K,Na)NbO3 Lead-Free Ceramics

Lee

2019

Energies

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“…Our previous study on the doping of KNNLS ceramics with Ti alone indicated lowering of the average grain size, dielectric constant, piezoelectric coefficients while the current density increases by many orders of magnitude [32]. Bismuth has been reported to increase the sintering temperature, average grain size, piezoelectric charge coefficient with ≤0.5 wt.% while the remnant polarization and coercive field are lowered.…”

Section: Resultsmentioning

confidence: 97%

Effect of bismuth titanate on the properties of potassium sodium niobate-based ceramics

Mgbemere

Akano

Schneider

2017

Journal of Asian Ceramic Societies

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The effect of modifying the properties of KNN-based ceramics with Bi 2 Ti 2 O 7 (BiT) been investigated in this work. The density measurements show that additions of BiT to the samples slightly increase the density values. Scanning electron microscope images of the samples indicate that the average sizes of the grains decrease with BiT addition while the volume of pores increase. X-ray diffraction results show that for (K 0.5 Na 0.5)NbO 3 based samples, a transformation from orthorhombic to pseudo-cubic phase is observed. For both K 0.48 Na 0.48 Li 0.04)(Nb 0.9 Ta 0.1)O 3 and K 0.48 Na 0.48 Li 0.04)(Nb 0.86 Ta 0.1 Sb 0.04)O 3-based compositions, the phase transition is from an orthorhombic-tetragonal coexistence to a tetragonal structure dominated phase coexistence. The dielectric constant, dielectric loss and resistivity values of the samples increase slightly with BiT addition. Good hysteresis curves are obtained in (K 0.5 Na 0.5)NbO 3-based samples only at low BiT amounts. Remnant polarization values between 9 C/cm 2 and 25 C/cm 2 are obtained for K 0.48 Na 0.48 Li 0.04)(Nb 0.9 Ta 0.1)O 3 and K 0.48 Na 0.48 Li 0.04)(Nb 0.86 Ta 0.1 Sb 0.04)O 3-based samples. With the exception of KNNLT samples where the d * 33 values increase from 203 ± 7 pm/V at 0 mol% to 275 ± 6 pm/V at 0.35 mol%, the d * 33 values of the samples gradually decrease with increasing BiT content. This work shows that to obtain good properties for KNN-based ceramics, only very small amounts of BiT are required.

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“…[2] Mgbemere and coworkers. 2015 [5] studied the effect of (Ti) on the properties of (KNN) based lead free ceramics. The results showed that the increasing of (Ti) dopant leads to decreasing the sintering temperature for each (1 %) of the dopant added.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Lead Free Piezoelectric Composite Based on Polyester Resin and (LKNN6-0.5%CeO2) Ceramic Particles

Chyad¹,

Farid²,

Kamal³

2016

ETJ

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For the sake of guarding the environment from the vital problems that results from the toxic effects of lead components, lead free (LKNN6-0.5%CeO 2 /polyester) piezoelectric composite are prepared in this work using cold press technique. Firstly, the lead free (LKNN6-0.5%CeO 2 ) piezoceramics are prepared using normal sintering technique. The dielectric and piezoelectric properties of the composites were examined as a function of the volume fraction of ceramic particles, all composites showed well dispersion of the piezoceramic particles in the polyester matrix as shown in SEM images. The piezoelectric and dielectric coefficients were found to be improved as the concentration of ceramic particles increases. Although the procedure is simple, the composite prepared in this study exhibited better piezoelectric and dielectric constants with (d 33 =41 and Ԑ r =157) at (80%) volume fraction.

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Effect of Ti on the properties of (KxNa1−x)NbO3 based lead-free ceramics

Cited by 3 publications

References 30 publications

Co-Doping Effect of BiGaO3 and (Bi,Na,K,Li)ZrO3 on Multi-Phase Structure and Piezoelectric Properties of (K,Na)NbO3 Lead-Free Ceramics

Co-Doping Effect of BiGaO3 and (Bi,Na,K,Li)ZrO3 on Multi-Phase Structure and Piezoelectric Properties of (K,Na)NbO3 Lead-Free Ceramics

Effect of bismuth titanate on the properties of potassium sodium niobate-based ceramics

Preparation of Lead Free Piezoelectric Composite Based on Polyester Resin and (LKNN6-0.5%CeO2) Ceramic Particles

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