Abstract In this work structural refinement, complex impedance spectroscopy (CIS) and Raman spectroscopy have been investigated on Na0.5(Bi1-xDyx)0.5TiO3 (xDyNBT) ceramic systems with x = 0, 2, 5 and 15%. The pure NBT, 2DyNBT and 5DyNBT compounds crystallize in a rhombohedral R3c structure while the 15DyNBT composition crystallizes in an orthorhombic Pnma structure. We reported that dysprosium addition affects the phase transition temperatures as well as the dielectric losses. The electrical transport at high temperatures was investigated using the CIS over a wide frequency range (10–106 Hz). The studied samples showed a non-Debye type process, with a short-range relaxation for the pure NBT and a coexistence of both localized and long-range relaxations of charge carriers for the 2DyNBT and 5DyNBT compounds. For the high concentration, 15DyNBT, a short-range relaxation is observed. Moreover, using a brick-layer model we discuss the resistance and capacitance of the different contributors (grain and grain boundaries) in our samples. High temperature Raman spectroscopy investigation was performed in order to follow the temperature evolution of the structural transformations on ferroelectric compounds. Anomalies in the temperature evolution of the vibrational modes are seen to correlate well with the temperature transitions observed from dielectric measurements.

中文翻译：

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Na0.5(Bi1-xDyx)0.5TiO3陶瓷的复阻抗和拉曼光谱

摘要 在这项工作中，对 x = 0、2、5 和 15% 的 Na0.5(Bi1-xDyx)0.5TiO3 (xDyNBT) 陶瓷体系进行了结构改进、复阻抗谱 (CIS) 和拉曼光谱研究。纯 NBT、2DyNBT 和 5DyNBT 化合物以菱形 R3c 结构结晶，而 15DyNBT 组合物以正交 Pnma 结构结晶。我们报道了镝的添加会影响相变温度以及介电损耗。使用 CIS 在很宽的频率范围 (10-106 Hz) 上研究了高温下的电传输。研究的样品显示出非德拜型过程，纯 NBT 的短程弛豫和 2DyNBT 和 5DyNBT 化合物的电荷载流子的局部和长程弛豫共存。对于高浓度，15DyNBT，观察到短程弛豫。此外，我们使用砖层模型讨论了样品中不同贡献者（晶界和晶界）的电阻和电容。进行高温拉曼光谱研究以跟踪铁电化合物结构转变的温度演变。振动模式的温度演化异常被认为与从介电测量中观察到的温度转变密切相关。进行高温拉曼光谱研究以跟踪铁电化合物结构转变的温度演变。振动模式的温度演化异常被认为与从介电测量中观察到的温度转变密切相关。进行高温拉曼光谱研究以跟踪铁电化合物结构转变的温度演变。振动模式的温度演化异常被认为与从介电测量中观察到的温度转变密切相关。