1 7O NQR study of the pseudo-one-dimensional ferroelectric phase transition in CsH2PO4

Abstract
The hydrogen bond dynamics of pseudo‐one‐dimensional CsH2PO4 has been studied in the paraelectric and ferroelectric phases by 17O–proton nuclear double resonance spectroscopy. The results show that the protons in the short one‐dimensionally linked O–H(2)‐‐O hydrogen bonds are moving between two equilibrium sites above Tc and freeze into one of the two off‐center sites below Tc. The protons in the asymmetric O–H(1)‐‐O bonds are static and ordered in the same way both above and below Tc and seem to play only a minor role in the transition mechanism.