Raman scattering study of Rb₃D_xH_1-x(SO₄)₂

Abstract

The Raman scattering spectra of the ν₂ mode of (SO₄)^2- ions in the zero-dimensional hydrogen-bonded crystal Rb₃D _x H_1-x (SO₄) (x = 0.2, 0.3, 0.51, 0.88) show anomalous broadening near T_c in the disordered phase. The inverse of the linewidth analyzed as one peak gives a mean characteristic time of proton and deuteron. Its temperature-dependence indicates a slight anomaly around 55 K. The influence of some quantum mechanical process like tunneling or zero-point vibration on the phase transition is discussed.

Key Words:

• Rb₃D _x H_1-x (SO₄)₂
• zero-dimensional hydrogen-bonded system
• Raman scattering
• proton motion
• motional narrowing theory
• tunneling
• zero-point vibration