Microstructural comparison between Nb- and Ta-systems in Li1+−M1−−3Ti+4O3 (M = Nb5+, Ta5+) solid solution with superstructure

Rapid Sintering of Li2O-Nb2O5-TiO2 Solid Solution by Air Pressure Control and Clarification of Its Mechanism

“…The period of 3 nm is 13 times that of (006), and corresponded to our previous result [7]. The intergrowth layers were formed by the diffusion of Ti ions; therefore it is easy to form the homogeneous phase when Ti content is larger [7,9]. These results show that the sintering temperature at 1273 K was insufficient for the formation of the homogeneous phase by controlling the air pressure system.…”

“…Smith and West (1992) reported that the homogeneous phase of LNT was synthesized at 1373 K after two to 10 days [1]. As previously reported, we synthesized Li-M-Ti-O (M: Ta, Nb) at 1393 K–1423 K for 72 h to 264 h [9]. We observed the LNT that was sintered under 0.35 MPa by the TEM image taken from the [100] axis and SAED, as shown in Figure 4.…”

“…One is to clarify the self-organized formation area of the superstructure. The second viewpoint is to compare the detailed microstructure between the Nb-solid and Ta-solid solutions [9]. …”

“…However, the synthesis of a homogeneous M-phase required treatment at 1373 K for over 24 h, and annealing was repeated several times to complete the reaction in an electric furnace [9]. The sintering time depended on the Ti content, and annealing was repeated for 24–264 h until a homogeneous structure was formed by the insertion of periodical intergrowth layers [9].…”

“…The sintering time depended on the Ti content, and annealing was repeated for 24–264 h until a homogeneous structure was formed by the insertion of periodical intergrowth layers [9]. Accordingly, a fast sintering technique that uses lower energy is required for the practical application of this material as phosphors and electroceramics.…”