ALKALINE NIOBATE-BASED PIEZOCERAMICS: CRYSTAL STRUCTURE, SYNTHESIS, SINTERING AND MICROSTRUCTURE

2010 ◽  
Vol 03 (01) ◽  
pp. 15-18 ◽  
Author(s):  
MARIJA KOSEC ◽  
BARBARA MALIČ ◽  
ANDREJA BENČAN ◽  
TADEJ ROJAC ◽  
JENNY TELLIER
Keyword(s):  
Crystal Structure ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Potassium Niobate ◽  
Promising Candidate ◽  
Sodium Potassium ◽  
Sodium Potassium Niobate ◽  
Structure Synthesis

In this review, the crystal structure and the synthesis of the sodium potassium niobate ( K 0.5 Na 0.5 NbO 3) as a promising candidate for lead-free piezoelectrics are addressed. The sintering and the microstructure as prerequisites for obtaining ceramics with reliable and sufficiently high piezoelectric properties for selected applications are discussed.

scholarly journals Processing and characterization of lead-free ceramics on the base of sodium–potassium niobate

2018 ◽  
Vol 08 (01) ◽  
pp. 1850004 ◽  
Author(s):  
E. D. Politova ◽  
N. V. Golubko ◽  
G. M. Kaleva ◽  
A. V. Mosunov ◽  
N. V. Sadovskaya ◽  
...  
Keyword(s):  
Piezoelectric Properties ◽  
Piezoelectric Materials ◽  
Lead Free ◽  
Potassium Niobate ◽  
Sodium Potassium ◽  
Sodium Potassium Niobate ◽  
Lead Free Ceramics ◽  
Donor And Acceptor ◽  
Perovskite Lattice

Lead-free sodium–potassium niobate-based piezoelectric materials are most intensively studied in order to replace the widely used Pb-based ones. In this work, the effects of modification of compositions by donor and acceptor dopants in the A- and B-sites of perovskite lattice on structure, dielectric, ferroelectric, and piezoelectric properties of ceramics from Morphotropic Phase Boundary in the ([Formula: see text])(K[Formula: see text]Na[Formula: see text])NbO3–[Formula: see text]BaTiO3 system and in compositions with [Formula: see text] and 0.06 additionally doped by Ni[Formula: see text] cations have been studied.

scholarly journals Hybrid Atmosphere Processing of Lead-Free Piezoelectric Sodium Potassium Niobate-Based Ceramics

Ceramics ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 460-471 ◽  
Author(s):  
Astri Bjørnetun Haugen
Keyword(s):  
Lead Free ◽  
Piezoelectric Response ◽  
Potassium Niobate ◽  
Sodium Potassium ◽  
New Approach ◽  
Sodium Potassium Niobate ◽  
Phase Pure ◽  
High Alkali ◽  
Surface Decomposition ◽  
Air Processing

K0.5Na0.5NbO3-based ceramics, a promising group of lead-free piezoelectrics, are challenging to sinter dense while avoiding alkali evaporation. This work explores hybrid atmosphere processing, a new approach where reducing atmospheres is used during heating to avoid coarsening from alkali carbonates and hydroxides, and oxidizing atmospheres is used during sintering to avoid alkali evaporation. Discs of Li0.06(K0.52Na0.48)0.94Nb0.71Ta0.29O3 with 0.25 mol% Mn (KNNLTM) were sintered in air, N2, 9% H2 in N2, or 9% H2 in N2 during heating and air during sintering (hybrid atmosphere processing). The highest density was obtained by sintering in 9% H2 in N2, but resulted in high alkali loss and decomposition of the surface, followed by low piezoelectric response. However, with the hybrid H2/air processing it was possible to both avoid surface decomposition and leakage currently associated with alkali evaporation during sintering in H2, and to obtain a denser, more phase-pure and small-grained KNNLTM ceramic with a higher piezoelectric response than obtained by sintering in air or N2.

Precursor Effect on Hydrothermal Synthesis of Sodium Potassium Niobate Fine Particles and Their Piezoelectric Properties

2011 ◽  
Vol 50 (9) ◽  
pp. 09ND09 ◽  
Author(s):  
Kiyoshi Kanie ◽  
Hideto Mizutani ◽  
Atsuki Terabe ◽  
Yoshiki Numamoto ◽  
Shintaro Tsukamoto ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Fine Particles ◽  
Piezoelectric Properties ◽  
Potassium Niobate ◽  
Sodium Potassium ◽  
Sodium Potassium Niobate

scholarly journals Sintering effect on electrical properties and morphology of lead-free Na0.92k0.08NbO3 ceramics

2019 ◽  
Vol 51 (4) ◽  
pp. 421-428
Author(s):  
Gambheer Kathait ◽  
N.S. Panwar ◽  
Prashant Thapliyal ◽  
Don Biswas ◽  
Vishal Rohilla ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Weight Ratio ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Potassium Niobate ◽  
Sodium Potassium ◽  
Reaction Method ◽  
Sodium Potassium Niobate ◽  
Pure Phase

Sodium potassium niobate (NKN) powders were synthesized by the solid-state reaction method. The NKN ceramics for composition Na0.92K0.08NbO3 (NKN) were then fabricated by a two-step sintering technique. The effects of the two-step sintering on the properties of the ceramics were investigated. The pure phase NKN was achieved for all sintering temperatures of 1100, 1150, 1200 and 1250?C. The observed change in the microstructure indicates that the grain size increases with the increasing sintering temperatures. Also, the two-step sintering technique produced a higher value of K/(K+Na) weight-% ratio and peak dielectric constant for sintering temperatures 1100, 1150 and 1200?C. However, further increasing of the sintering temperatures at 1250?C, reduces the K/(K+Na) weight-% ratio and the peak dielectric constant (?c).

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