Study of the structural properties and phase transitions of LiCs1−x(NH4)xSO4 (x = 0.1 and 0.4) mixed crystals by 1H, 7Li, and 133Cs nuclear magnetic resonance

LiCs1−x(NH4)xSO4 (x = 0.1 and 0.4) mixed crystals were grown using the slow evaporation method, and their lattice constants were determined with X-ray diffraction. The structural properties and phase transitions of the LiCs1−x(NH4)xSO4 mixed crystals were studied by 1H, 7Li, and 133Cs nuclear magnetic resonance relaxation analyses and differential scanning calorimetry. On the basis of the results, along with previous reports on the structural properties of pure LiCsSO4 and LiNH4SO4 single crystals, the effects of partially replacing cesium ions with ammonium ions were examined. The results showed that the introduction of a small quantity of ammonium ions into LiCsSO4 crystals induces a change in the phase transition temperatures and causes the ferroelastic properties to almost completely disappear.