Coordination Funds

极性氧化物锂-钽酸锂固溶体（LNT）由于其在整个组成范围内的相容性和铁电畴的可调尺寸而代表了新的基础材料和物理现象的公开和应用的非常可变的模型系统。点缺陷和畴壁对宏观材料性质的影响、它们的相互作用和高热稳定性为压电结构（例如致动器和声学晶体）提供了新颖且广泛的新兴应用，但同样也为纳米电子和非线性以及高达高温的光电应用提供了新颖且广泛的新兴应用。特别是，我们预期化学计量和畴结构的预期调整允许定制晶体性质，例如，利用高压电系数和预期的高畴壁电导率。研究小组的目标包括缺陷结构的确定，理解和关联，在宽的温度范围内，特别是在高温下，极性氧化物中的电子和原子输运和声学损失。首先，将建立不同化学计量的单畴晶体中的点缺陷的理解，以便随后可以实现对畴壁对点缺陷，原子输运和宏观晶体性质的影响的新见解。主要关注的是材料科学和物理问题，其中包括缺陷的识别，如极化子和低维区域中电荷载流子的传输。我们的研究结果可能对其他材料系统也有更大的影响，这为未来的项目阶段开辟了光明的前景。在我们的初步工作中，LNT晶体的制备，通过直拉法生长和其特征在于在其电气性能。此外，还演示了晶体的极化和畴结构的可视化。参与的科学家提供了互补的能力，从晶体生长到离子输运研究和极化子动力学，到畴和畴壁结构，机电特性和高级建模。这保证了这个新的研究领域增加了效益，如果没有目前的财团，这是不可能的。这就产生了协同效应，而协同效应是实现研究理念的前提条件。同时，将建立两个初级研究小组，并可持续地支持高素质博士生和本科生的教育。

Polar oxidic lithium niobate-lithium tantalate solid solutions (LNT) represent an extraordinarily variable model system for the disclosure and application of new fundamental materials and physical phenomena due to their miscibility over the entire compositional range and the tunable size of ferroelectric domains. The impact of point defects and domain walls on macroscopic material properties, their interaction and high thermal stability provide a novel and broad range of emerging applications for piezoelectric structures such as actuators and acoustic crystals, but equally for nanoelectronic and nonlinear and optoelectronic applications up to high temperatures. In particular, we anticipate that the intended adjustment of stoichiometry and domain structure allows to tailor the crystal properties and, for example, to take advantage of the high piezoelectric coefficients and the expected high domain wall conductivity.The objectives of the research group include the determination, understanding and correlation of defect structures, electronic and atomic transport and acoustic losses in polar oxides over a wide temperature range, especially at high temperatures. Initially, the understanding of point defects in monodomain crystals of different stoichiometry will be established, so that subsequently new insights into the impact of domain walls on point defects, atomistic transport and macroscopic crystal properties can be achieved. The main focus is on material science and physics issues, which include the identification of defects such as polarons and the transport of charge carriers in low-dimensional regions. Our results might have a larger impact to other material systems as well, which opens a bright perspective for future project phases. Within our preliminary work, LNT crystals were prepared by Czochralski growth and characterized in terms of their electrical properties. Furthermore, poling of crystals was demonstrated and the domain structure was visualized.The scientists involved provide complementary competences, ranging from crystal growth over ion-transport investigation and polaron dynamics to domain and domain-wall structure, electromechanical properties and advanced modelling. This guarantees added benefit into this novel research field, which would not be possible without the present consortium. This leads to synergy, which is the precondition for the realization of the research concept. Simultaneously, two junior research groups will be established and the education of highly qualified PhD students and undergraduates is supported sustainably.