Pressure induced band gap narrowing and phase transitions in Dy2Ti2O7

被引：6

作者：

Li, Xin ^{[1
,2
]}

Yan, Zhipeng ^{[2
]}

Rahman, Saqib ^{[2
]}

Zhang, Jinbo ^{[2
,3
]}

Yang, Ke ^{[4
]}

Li, Xiaodong ^{[5
]}

Kim, Jaeyong ^{[6
]}

Sun, Xuefeng ^{[7
,8
,9
]}

Wang, Lin ^{[2
,10
]}

机构：

[1] Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China

[2] Ctr High Pressure Sci & Technol Adv Res, Shanghai 201203, Peoples R China

[3] Yangzhou Univ, Coll Phys Sci & Technol, Yangzhou 225002, Jiangsu, Peoples R China

[4] Chinese Acad Sci, Shanghai Inst Appl Phys, Shanghai 201203, Peoples R China

[5] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China

[6] Hanyang Univ, Dept Phys, HYU HPSTAR CIS High Pressure Res Ctr, Seoul 04763, South Korea

[7] Univ Sci & Technol China, Dept Phys, Hefei Natl Lab Phys Sci Microscale, Hefei 230026, Anhui, Peoples R China

[8] Univ Sci & Technol China, Key Lab Strongly Coupled Quantum Matter Phys CAS, Hefei 230026, Anhui, Peoples R China

[9] Anhui Univ, Inst Phys Sci & Informat Technol, Hefei 230601, Anhui, Peoples R China

[10] Yanshan Univ, Ctr High Pressure Sci CHiPS, State Key Lab Metastable Mat Sci & Technol, Qinhuangdao 066004, Hebei, Peoples R China

来源：

JOURNAL OF PHYSICS-CONDENSED MATTER | 2020年 / 32卷 / 21期

基金：

新加坡国家研究基金会; 中国国家自然科学基金;

关键词：

pyrochlore; high pressure; phase transition; band gap; RE2TI2O7; RE; EARTH;

D O I：

10.1088/1361-648X/ab6f82

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

An isostructural phase transition and a cubic to tetragonal phase transition in spin-frustrated pyrochlore Dy2Ti2O7 (DTO) at 35 GPa and 46 GPa, respectively, were detected by x-ray diffraction (XRD) and Raman spectroscopy studies at room temperature under high pressure. The band gap of DTO gradually increased with the increasing pressure up to 20 GPa, after which it narrowed significantly around 35 GPa, and further manifested with a slight discontinuity around 46 GPa. Below 35 GPa, the evolution of band gap with pressure maintained a close relationship with the Ti-O bond length and the distortion of TiO6 octahedron. The remarkable narrowing of the band gap around 35 GPa implied the changes of the band structure and confirmed the isostructural phase transition. These findings provide an in-depth understanding of the evolution of the structure and the band gap of DTO under high pressure.

引用

页数：7

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