The Influence of High Ammonium Concentration in Ferroelectric-Antiferroelectric Mixed crystals Rb1-x(ND4)xD2AsO4 by Raman Scattering
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 an...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
1997
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| Online Access: | http://ndltd.ncl.edu.tw/handle/29082897960776210946 |
| Summary: | 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.
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