We have studied the microscopic structure and dynamics in a proton-irradiated $\mathrm{K}{\mathrm{H}}_2\mathrm{P}{\mathrm{O}}_4$ single crystal. Our ${}^1\mathrm{H}$ and ${}^{31}\mathrm{P}$ nuclear magnetic resonance measurements indicate that proton irradiation gives rise to a decrease in the local dipolar order of the rigid lattice protons and an increase in interstitial protons as well as structural distortion of the $\mathrm{P}{\mathrm{O}}_4$ tetrahedra.

• Received 2 May 2007

DOI:https://doi.org/10.1103/PhysRevB.76.172101