New ferroelastic properties and the paraelectric-ferroelectric-paraelectric phase transitions of Rochelle salt

作者：Lim Ae Ran^*; Lee Kwang Sei

来源：Journal of Applied Physics, 2011, 110(3): 033520.

DOI：10.1063/1.3618679

The NMR spectra and the spin-lattice relaxation times, T-1, of Rochelle salt crystals were studied as functions of temperature. Two groups of resonance lines were found in the Na-23 and K-39 NMR spectra of the paraelectric phases below T-C1 and above T-C2, whereas four groups of resonance lines were obtained in the Na-23 and K-39 NMR spectra of the ferroelectric phase between T-C1 and T-C2. To investigate the extra two groups of resonance lines in the ferroelectric phase, the stress-strain hysteresis loop of the Rochelle salt crystal was obtained, and the ferroelastic character of the Rochelle salt crystals suggested by Sapriel's theory was established by the relationship between the Na-23 and K-39 NMR spectra and the stress-strain hysteresis loop results. Therefore, ferroelastic and ferroelectric properties coexist in the phase between T-C1 and T-C2.

• 出版日期2011-8-1