Lattice parameters and tilted octahedra in sodium–potassium niobate solid solutions

Unusual Phase Behavior in the Piezoelectric Perovskite System, LixNa1–xNbO3

“…8,9 Moreover, the orthorhombic ferroelectric phase of NaNbO 3 can be made via chemical doping; indeed doping as little as 2% of either potassium or lithium, to form the solid solutions K x Na 1-x NbO 3 or Li x Na 1-x NbO 3 , induces both a change in the octahedral tilt system of Phase P and a polarization to produce Phase Q. 10 The composition-dependent phase diagram of KNN has recently been re-analysed and is now fairly well understood, 11,12 but that of LNN has received much less attention. However, several previous studies 13 , 14 , 15 point to both interesting electrical properties and also curious phase behavior for the LNN system, which prompts a more thorough re-appraisal of the chemistry and crystallography of this solid solution.…”

Structures of K0.05Na0.95NbO3 (50–300 K) and K0.30Na0.70NbO3 (100–200 K)

“…The original phase diagram of KNN at room temperature and above was reported by Ahtee & Glazer (1976). In the phase diagram, three phase boundaries at room temperature were indicated at around x ' 0:50, x ' 0:32 and x ' 0:18.…”

Antiferroelectricity induced by electric field in NaNbO3-based lead-free ceramics

“…NaNbO 3 is a perovskite compound known for its complex structures and phase transitions. [13][14][15][16][17] Its solid solutions are of technological importance due to applications in lead-free piezoelectric devices [18][19][20] and high-temperature capacitors. 21 Although NaNbO 3 has been investigated for more than six decades, researchers are still debating whether it is antiferroelectric or ferroelectric at room temperature.…”

“…AgNbO 3 was included to enhance the reversibility of the phase transition, 22,23 while the amount of KNbO 3 was adjusted to locate the antiferroelectric/ferroelectric phase boundary. 13,15,18 To prepare the ceramics, mixtures of Ag 2 O, Na 2 CO 3 , K 2 CO 3 , and Nb 2 O 5 were calcined at 900 C for 4 h. The calcined powders were then milled for 7 h and dried. The pressed pellets were sintered at 1250-1310 C for 4 h in air.…”