Raman Investigation of Sodium Titanate Nanotubes under Hydrostatic Pressures up to 26.9GPa

• 作者: 刘冰冰 崔启良 崔田 李雪飞 杜祖亮 田宝丽 邹广田 马艳梅
• 来源期刊: 中国物理快报(英文版)
• 学科: 化学
• 关键词: 钛酸纳米管 静水压力 拉曼光谱 钠 金刚石压腔 不可逆相变 行为调查 晶格畸变
• 年，卷（期）: 2010,（2）
• 页码范围: 199-202
• 页数: 4页
• 分类号: O614.411 TU457
• 语种: 英文

摘要

High pressure behavior of sodium titanate nanotubes (Na2Ti2O5) is investigated by Raman spectroscopy in a diamond anvil cell (DAC) at room temperature. The two pressure-induced irreversible phase transitions are observed under the given pressure. One occurs at about 4.2 GPa accompanied with a new Raman peak emerging at 834 cm-1 which results from the lattice distortion of the Ti-O network in titanate nanotubes. It can be can be assigned to Ti-O lattice vibrations within lepidocrocite-type (H0.7Ti1.825V0.175O4?H2O)TiO6 octahedral host layers with V being vacancy. The structure of the nanotubes transforms to orthorhombic lepidocrocite structure. Another amorphous phase transition occurs at 16.7 GPa. This phase transition is induced by the collapse of titanate nanotubes. All the Raman bands shift toward higher wavenumbers with a pressure dependence ranging from 1.58-5.6 cm-1/GPa.