Orthorhombic and monoclinic ferroelectric phases investigated by Raman spectroscopy in PZN-4.5 % PT and PZN-9 % PT crystals

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• 作者：Mimoun El Marssi ; Hichem Dammak
• 关键词：A. Ferroelectrics ; C. Crystal structure and symmetry ; D. Phase transitions ; E. Raman spectroscopy
• 刊名：Solid State Communications
• 出版年：2007
• 出版时间：June 2007
• 年：2007
• 卷：142
• 期：9
• 页码：487-491
• 全文大小：709 K

文摘

Polarized Raman spectra measurements have been performed on orientated single crystals of Pb[(Zn_1/3Nb_2/3)_0.955Ti_0.045]O₃ (PZN-4.5 % PT) and Pb[(Zn_1/3Nb_2/3)_0.91Ti_0.09]O₃ (PZN-9 % PT) poled by an electric field along the pseudo-cubic direction in order to determine the nature of the induced ferroelectric phases. Under field-cooled (FC) conditions the ferrolectric phase transition sequence, tetragonal–orthorhombic–rhombohedral, was observed in PZN-4.5 % PT. Comparison between the phase transitions induced in PZN-9 % PT and PZN-4.5 % PT crystals in FC shows that the low- temperature ferroelectric phase in PZN-9 % PT cannot be orthorhombic and it can be attributed to the monoclinic phase. The characteristic temperatures found by Raman spectroscopy correspond to those obtained by dielectric measurements and by X-ray diffraction reported previously.