Anharmonic coupling between fundamental modes in tetramethylurea.
In situ high pressure Raman spectra of tetramethylurea have been measured up to 25 GPa, liquid-solid and solid-solid phase transitions were detected at 0.2 GPa and 7.4 GPa, respectively. An unprecedented spectral phenomenon is the observation of a Fermi resonance between the fundamental modes. An exponential relationship between the intensity and the frequency difference was concluded. Pressure provides us a new way to study the correlation between Fermi resonance parameters.
State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China.
Yuanzheng
Y
Chen
College of Physics, Jilin University, Changchun130012, People's Republic of China.
Zhiwei
Z
Men
College of Physics, Jilin University, Changchun130012, People's Republic of China.
Juntao
J
Li
College of Physics, Jilin University, Changchun130012, People's Republic of China.
Zhanlong
Z
Li
College of Physics, Jilin University, Changchun130012, People's Republic of China.
Shengnan
S
Sun
College of Physics, Jilin University, Changchun130012, People's Republic of China.
Chengling
C
Sun
College of Physics, Jilin University, Changchun130012, People's Republic of China.
Shuqin
S
Gao
College of Physics, Jilin University, Changchun130012, People's Republic of China.
Zuowei
Z
Li
State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China.
Mi
M
Zhou