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Nakai, Tomoaki*; Kobune, Masafumi*; Nagamoto, Takeru*; Kikuchi, Takeyuki*; Yoneda, Yasuhiro
Transactions of the Materials Research Society of Japan, 41(3), p.251 - 254, 2016/09
Solid solutions of NaNbO and KNbO are the candidate for non-Pb piezoelectric materials. It is difficult to obtain dense ceramics owing to the difference of their calcination temperature. We developed the malic acid complex method to obtain the (NaKLi)NbO to obtain a high-quality ceramics sample. It was found that (NaKLi)NbO lies complicated phase boundaries; one is the structural phase boundary between NaNbO and KNbO, the other is that between (Na,K)NbO mixture and LiNbO, which is a sintering additive.
Yoneda, Yasuhiro; Nagamoto, Takeru*; Nakai, Tomoaki*; Kobune, Masafumi*
Transactions of the Materials Research Society of Japan, 41(2), p.197 - 200, 2016/06
BiNaTiO (BNT) has been investigated as a lead-free piezoelectric material. We have already performed structure analysis of BNT. The average structure of BNT with low-temperature synthesis is a rhombohedral structure and it becomes a monoclinic structure as the synthesized temperature increases. Our local structure analysis indicated that the -site atoms of Bi and Na displaced toward different position depending on the lattice expansion and construction. We synthesized BNT crystals with various substitution and performed local structure analysis to examine the hypothesis. The local structure analysis revealed that the substitution effect on BNT can be explained by our hypothesis.