1998 Fiscal Year Final Research Report Summary
Superstructure and microwave property of Lithium niobate solid solution
| Project/Area Number |
09650740
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | Ryukoku University |
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Principal Investigator |
URABE Kazuyori Ryukoku University, Faculty of Science and Technology, Department of Materials Chemistry, Professor, 理工学部, 教授 (50016383)
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| Co-Investigator(Kenkyū-buntansha) |
SHIRAKAMI Tatsuya Ryukoku University, Faculty of Science and Technology, Department of Materials C, 理工学部, 助手 (50257416)
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| Project Period (FY) |
1997 – 1998
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| Keywords | lithium niobate / solid solution / superstructure / microwave / TEM / simulation / sol-gel method / titania |
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| Research Abstract |
We synthesized two series of lithium niobate solid solutions, i.e., Li_<1+x>Nb_<1-x>Ti_xO_3 and Li_<1.1-y>Nb_<0.9-3y>Ti_<0.1+4y>O_3. All of the X-ray diffraction patterns of these specimens were similar to that of LiNbO_3 except for the presence of characteristic satellite reflections. Therefore all specimens were identified to be phase M.The splitting width of satellite reflections and the density increased with increasing the titania composition.
The structure images of two specimens, Li_<1.15>Nb_<0.85>Ti_<0.15>O_3 and Li_<1.3>Nb_<0.7>Ti_<0.3>O_3, were observed using a transmission electron microscope. The superstructure periodicity of Li_<1.15>Nb_<0.85>Ti_<0.15>O_3 and Li_<1.3>Nb_<0.7>Ti_<0.3>O_3 were 44A and 32A, respectively. Thick domain boundary zones were also observed in both specimens. That of Li_<1.15>Nb_<0.85>Ti_<0.15>O_3 and Li13Nb07Ti03O3 were 4 A and 7A, In these electron diffraction patterns, the satellite reflections were clearly observed near reciprocal lattice points with h0l indices forming rows along the c* axis of the subcell. We proposed a structural model on the basis of the TEM observations. The Diffraction pattern that was calculated by a computer simulation based on the model well reproduced the actual patterns.
The X-ray diffraction pattern of the specimen, which was synthesized by sol-gel method andtreated at 900ﾟC had already the superstructure reflections. The fact means the possibility of the synthesis at low temperature less than 1000ﾟC.
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