Growth, Characterization, and Raman spectra of the 1T phases of TiTe2, TiSe2, and TiS2
Growth, Characterization, and Raman spectra of the 1T phases of TiTe2, TiSe2, and TiS2
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TiTe2、TiSe2 和 TiS2 1T 相的生长、表征和拉曼光谱
DOI：
10.1088/1674-1056/ac306a
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发表时间：
2021-10
影响因子：
1.7
通讯作者：
Jian-Qiao Meng
中科院分区：
文献类型：
--
作者：
Xiao-Fang Tang;Shuang-Xing Zhu;Hao Liu;Chen Zhang;Qi-Yi Wu;Zi-Teng Liu;Jiao-Jiao Song;Xiao Guo;Yongsong Wang;He Ma;Yin-Zou Zhao;Fan-Ying Wu;Shu-Yu Liu;Kaihui Liu;Ya-Hua Yuan;Han Huang;Jun He;Wen Xu;Haiyun Liu;Yu-Xia Duan;Jian-Qiao Meng
使用碘作为传输剂，通过化学气相传输生长了高质量的大 1T 相 TiX 2 （X= Te、Se 和 S）单晶。通过成分和结构分析对样品进行表征，并通过拉曼光谱研究其特性。已经观察到了几种声子模式，包括广泛报道的 A 1g 和 E g 模式，很少报道的 Eu 模式（TiTe 2 为 ∼ 183 cm−1，TiS 2 为∼ 185 cm−1），甚至 TiTe 2 意想不到的 K 模式（∼ 85 cm−1）。大多数声子随着温度的降低而硬化，除了 TiTe 2 的 K 模式和 Eu 和" A 2u/Sh" 模式 TiS 2 随温度降低而软化。此外，我们还发现TiSe 2 中声子的变化可能与电荷密度波相变有关。我们对 TiX 2 声子的研究结果将有助于理解它们的电荷密度波和超导性。
High-quality large 1T phase of TiX 2 (X= Te, Se, and S) single crystals have been grown by chemical vapor transport using iodine as a transport agent. The samples are characterized by compositional and structural analyses, and their properties are investigated by Raman spectroscopy. Several phonon modes have been observed, including the widely reported A 1g and E g modes, the rarely reported E u mode (∼ 183 cm− 1 for TiTe 2, and∼ 185 cm− 1 for TiS 2), and even the unexpected K mode (∼ 85 cm− 1) of TiTe 2. Most phonons harden with the decrease of temperature, except that the K mode of TiTe 2 and the E u and" A 2u/Sh" modes of TiS 2 soften with the decrease of temperature. In addition, we also found phonon changes in TiSe 2 that may be related to charge density wave phase transition. Our results on TiX 2 phonons will help to understand their charge density wave and superconductivity.