Charge Distribution of O-H center dot center dot center dot O Bonds in Proton-Irradiated KH2PO4 Ferroelectrics

Abstract

The mechanism of charge distribution has been probed by measuring the H-1 chemical shift on a proton-irradiated KH2PO4 (KDP) single crystal. For high-resolution H-1 chemical shift measurements, the CRAMPS (combined rotation and multiple pulse sequence) technique is utilized. The proton irradiation caused an increase in H-1 chemical shift that can be interpreted as an electronic charge transfer from the proton to an oxygen atom, accompanied by a displacement of the proton along the hydrogen bond. The calculated Morse potentials can be explained by using evidence of electronic instabilities related to the proton displacive features.