Remote access to electrical conductivity in ion conducting solids by means of charge carrier attachment from a fs-laser plasma

离子传导固体材料的导电性将通过电荷附着诱导传输（CAIT）技术，从飞秒激光产生的等离子体的电荷载体的基础上进行研究。基本工作原理已在初步工作中得到证明。这一方法将得到确立、进一步发展并应用于最先进的科学问题。fs激光电离允许在构成等离子体的条件下在可调节的压力和温度下形成多种化学电荷载流子，例如氧阴离子和阳离子、质子、电子、稀有气体阳离子等。从等离子体到固体样品的极性选择的电荷载流子的附着导致产生明确定义的电化学电势梯度，这又诱导样品中的电荷载流子传输。输运系数可以从电流-电压测量或从浓度深度分布的分析中得出。该方法的独特卖点在于，在软条件下，大量的电荷载体可以附着到样品上，并且仅触发实际的电扩散传输。与大多数已建立的技术相比，Plasma-CAIT仅在样品和金属电极之间进行一次接触，在该接触处将测量电流。等离子体构成具有明确的电化学势的虚拟电极。通过这种方法可以严格避免阻塞区。该方法构成了一个远程访问的电导率的条件下，直流运输相关的所有电池和燃料电池的应用。该项目的一个目标是开发一种绝对电导率的测量程序，从而避免单独校准测量的需要。总的测量计划覆盖从毫巴到几巴的范围，重点是环境条件。温度和最终的相对湿度也将受到控制。等离子体CAIT技术将进一步发展的锂铝锗磷酸盐（LAGP）的例子，一个重要的离子导体，并随后应用到一个典型的高温燃料电池材料，即钇稳定的氧化锆（YSZ）。通过这些研究获得的额外科学知识涉及天然电荷载体的明确识别和元素特定传输系数的确定，包括离子传导固体中氧离子、锂离子和质子的部分传输系数。

The electrical conductivity of ion conducting solid materials will be studied by means of the charge attachment induced transport (CAIT) technique, based on charge carriers from a fs-laser generated plasma. The underlying working principles has been proven in preliminary work. The approach shall be established, further advanced and applied to state-of-the-art scientific questions. The fs-laser ionization allows formation of a diversity of chemical charge carriers, e.g. oxygen anions and cations, protons, electrons, rare gas cations etc. at adjustable pressure and temperature under conditions which constitute a plasma. Attachment of polarity selected charge carriers from the plasma to a solid sample leads to the generation of well-defined gradients of the electrochemical potential, which in turn induces charge carrier transport in the sample. Transport coefficients can be either derived from current-voltage measurements or from the analysis of concentration depth profiles. The unique selling point of the approach is that a large variety of charge carriers can be attached to a sample under soft conditions and only triggers the actual electro-diffusive transport. In contrast to most established techniques, the Plasma-CAIT operates with only one contact between the sample and a metal electrode, at which the current will be measured. The plasma constitutes a virtual electrode with well-defined electro-chemical potential. Blocking zones can be rigorously avoided by this approach. The approach constitutes a remote access to electrical conductivity under conditions of DC-transport as relevant for all battery and fuel cell applications. One goal of the project is the development of a measuring routine for absolute conductivities circumventing the need for separate calibration measurements. In total measurement are planned to cover a range from mbar to several bar, with an emphasis on ambient conditions. Temperatures and eventually relative humidity will also be controlled. The Plasma-CAIT technique will be further developed for the example of Lithium-Aluminum-Germanium-Phosphate (LAGP) an important ion conductor and subsequently applied to a typical high temperature fuel cell material, i.e. yttrium stabilized zirconia (YSZ). The additional scientific knowledge gained by these studies pertains to the unambiguous identification of native charge carriers and the determination of element-specific transport coefficients, including partial transport coefficients for oxygen ions, lithium ions and protons in ion conducting solids.