Low-temperature phase transition of a crystal in the lithium sodium niobate system

Noncentrosymmetric phase of submicron NaNbO3 crystallites

“…NaNbO 3 on the other hand, shows a much more complex transition characteristic through the displacement of Nb ions and tilting of NbO 6 -octahedra [10,11]. At room temperature, this material is antiferroelectric [9] but certain other oxides dissolved in NaNbO 3 promote a transition from the antiferroelectric to the ferroelectric state [9,12,13]. Recently we found a noncentrosymmetric crystal structure of NaNbO 3 for crystallites with reduced dimensions (200-400 nm) [14].…”

Temperature-dependent Raman spectra of K0.2Na0.8NbO3 ceramics

“…X-ray diffraction studies have shown that the production of a solid solution with Li content of 3% at in NaNbO 3 Li 0.03 Na 0.97 NbO 3 is enough to change the perovskite-like original structure to an orthorhombic one with space group Pc2 1 b C 2v 5 . 11 In addition, the lowtemperature phase of Li 0.03 Na 0.97 NbO 3 is rhombohedric with space group R3c C 3v 6 . However, Zhong et al 11 did not take into account the effects of grain size and strain that might also play an important role in determining the phase transition sequence.…”

“…11 In addition, the lowtemperature phase of Li 0.03 Na 0.97 NbO 3 is rhombohedric with space group R3c C 3v 6 . However, Zhong et al 11 did not take into account the effects of grain size and strain that might also play an important role in determining the phase transition sequence.…”

Effect of particle size and strain on phase stability of (Li0.06 Na0.94) NbO3

“…5,[14][15][16][17][18][19][20][21][22][23][24][25][26] For the compositions x < 0.10, the oxygen octahedra are linked by corner, and are linked together by common faces for x > 0.12. Krainik 14 has reported that LNNx exhibits antiferroelectric phase up to x ¼ 0.01, and becomes ferroelectric with increasing Li concentration.…”

“…For x ¼ 0.02, Sadel et al 18 have observed very small peak in dielectric constant at about 163 K and suggested a transition from orthorhombic to rhombohedral phase. Zhong et al 19 have studied the low temperature phase transition for x ¼ 0.03 using dielectric measurements which show a large thermal hysteresis of transition about 80 K. This is ascribed to the large structural change required at the transition which indicates that the transition is sluggish. Wang et al 20 have studied dielectric and pyroelectric properties for the composition x ¼ 0.06.…”