Temperature-dependent second harmonic generation in (LiRbSO4)-Li-6 and (LiRbSO4)-Li-7

Abstract

Temperature-dependent second harmonic generation efficiencies of (LiRbSO4)-Li-6 and (LiRbSO4)-Li-7 have been measured across the ferroelectric phase TV region (166 - 185 degrees C), using the crystalline powder of 38 - 63 mu m particle size range. The transition temperatures have not been changed by the lithium isotope substitution. More polarizable (LiRbSO4)-Li-6 has higher second harmonic generation efficiency than (LiRbSO4)-Li-7 up to 10%. We obtain unbalanced twin-peak-shaped patterns of thermal hysteresis. The unique hysteresis pattern of LiRbSO4 is ascribed to the very narrow temperature region of the phase IV, and to the overlapping of two hysteresis curves with very different widths.