Neutron and high pressure X ray diffraction study of hydrogen bonded ferroelectric rubidium hydrogen sulfate.
The pressure and temperature dependent phase transitions in the ferroelectric material rubidium hydrogen sulfate (RbHSO4) are investigated by a combination of neutron Laue diffraction and high pressure X ray diffraction. The observation of disordered O atom positions in the hydrogen sulfate anions is in agreement with previous spectroscopic measurements in the literature. Contrary to the mechanism observed in other hydrogen bonded ferroelectric materials, H atom positions are well defined and ordered in the paraelectric phase. Under applied pressure RbHSO4 undergoes a ferroelectric transition before transforming to a third, high pressure phase. The symmetry of this phase is revised to the centrosymmetric space group P21/c, resulting in the suppression of ferroelectricity at high pressure.
Acta crystallographica Section B, Structural science, crystal engineering and materials