Neutron and high‐pressure X‐ray diffraction study of hydrogen‐bonded ferroelectric rubidium hydrogen sulfate. Issue 6 (2nd December 2016) - Binns, Jack
Abstract : The hydrogen‐bonded ferroelectric material rubidium hydrogen sulfate has been investigated through a combination of high‐pressure X‐ray diffraction and neutron Laue diffraction. This study confirms the order–disorder origin of the ferroelectric transition as well as fully characterizing the high‐pressure phase transition. Abstract : 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 P 21 / c, resulting in the suppression of ferroelectricity at high pressure.