Hydrogen potentials and wave functions in KDP and KHCO 3

Abstract

We have performed neutron incoherent scattering experiments to investigate proton dynamics in KH 2PO 4 (KDP), KD 2PO 4 (DKDP), KHCO 3 and KDCO 3. Their hydrogen excitation spectra and the Q -maps of the neutron scattering function S( Q , ɛ) are observed. From these S( Q , ɛ), the hydrogen potentials are precisely determined, and their isotope effects on the phase transition temperature are discussed in a whole system of the proton and the lattice.