论文标题
na $ _ {0.5} $的复杂阻抗和拉曼光谱（bi $ _ {1-x} $ dy $ _x $）$ _ {0.5}
Complex impedance and Raman spectroscopy of Na$_{0.5}$(Bi$_{1-x}$Dy$_x$)$_{0.5}$TiO$_3$ ceramics
论文作者
论文摘要
在这项工作结构的完善中，已经对Na $ _ {0.5} $（BI $ _ {1-x} $ _ {1-x} $ _x $）进行了研究，对复杂的阻抗光谱和拉曼光谱进行了研究。纯NBT，2DYNBT和5DYNBT化合物在菱形结构中结晶，而15dynbt组成在正骨PNMA结构中结晶。我们报道说，肾上腺肿块的增加会影响相变温度以及介电损失。使用CIS在较大频率范围内研究了高温下的电运输。研究的样品显示出非偏僻的类型过程，纯净NBT的短程松弛以及2DYNBT和5DYNBT化合物的电荷载体的局部和远距离弛豫的共存。对于高浓度，15dynbt，观察到短距离松弛。此外，使用砖层模型，我们讨论了样品中不同贡献者（晶粒和晶界）的抗性和电容。进行高温拉曼光谱研究，以遵循铁电化合物上结构转化的温度演变。振动模式的温度演化中的异常被认为与从介电测量值中观察到的温度转变良好相关。
In this work structural refinement, complex impedance spectroscopy, and Raman spectroscopy have been investigated on Na$_{0.5}$(Bi$_{1-x}$Dy$_x$)$_{0.5}$TiO$_3$ (xDyNBT) ceramic systems. The pure NBT, 2DyNBT and 5DyNBT compounds crystallize in a rhombohedral 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. 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.
