The Influence of High Ammonium Concentration in Ferroelectric-Antiferroelectric Mixed crystals Rb1-x(ND4)xD2AsO4 by Raman Scattering

• Main Authors: 330 002M 86-20, 趙仁志
• Other Authors: 杜繼舜
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/29082897960776210946

碩士 === 輔仁大學 === 物理學研究所 === 85 === The mixed crystals of Rb1-x(ND4)xD2AsO4 were grown from aqueous solution with certain ratios of RbD2AsO4 (DRDA) and ND4D2AsCO4 (DADA), which are ferroelectric (FE) and antiferroelectric (AFE) crystals, respectively. The Raman spectra of A1-y(zz)x, B2-y(xy)x and E-y(xz)x symmetries have been measured as a function of temperature from 80 to 300 K. From the temperature-dependent Raman frequencies of the AsO4 group, various phase transitions or phase coexistence were observed in different compounds . The temperature-dependent anomalies were mainly attributed to the competition between FE and AFE orderings. The random distribution of Rb+ and ND4 ions is the main cause to produce frustration which can suppress the long-range electric order. It is also responsible for the formation of deuteron-glass state occurred specially in the low-temperature region.