Structural transitions in NaNH2 via recrystallization under high pressure

• 来源期刊: 中国物理B（英文版）
• 关键词: high pressure sodium amide phase transition recrystallization
• 年，卷（期）: 2019,（9）
• 页码范围: 346-351
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/ab37f8

摘要

Multiple phase transitions are detected in sodium amide (NaNH2),an important hydrogen storage material,upon compression in diamond anvil cells (DAC) by using Raman spectroscopy and x-ray diffraction (XRD) measurements.Additional Bragg reflections appear on lower and higher angle sides of the original ones at ～ 1.07 GPa and 1.84 GPa,accompanied by obvious changes in Raman spectroscopy,respectively.It reveals that NaNH2 undergoes the high-pressure phase sequence (α-β-γ) up to 20 GPa at room temperature.Spectral analysis indicates an orthorhombic structure with PBAN space group for the γ phase.We also experimentally observe high pressure induced recrystallization in alkaline amide compounds for the first time.