Synthesis, structure, and properties of selected ZrCuSiAs type pnictide oxides and related compounds

该项目有三个关键主题，即(I)RETPnO材料合成条件的改进和RE-T-Pn-O和RE-T-Pn-O-Cl系的探索性合成，包括结构研究，(Ii)选定的RETPnO相的磁学、电学和比热数据的研究，以及(Iii)含RE(AE)T2Pn2和RETPnO相的系统的57FeöçBauer谱研究。制备部分是合成用于物理性能测量的高质量X射线纯样品不可缺少的部分。有多种制备技术(电弧法、感应熔炼法、金属或盐熔剂合成法)可用。所有样品将进行详细的粉末X射线衍射和金相分析，并结合能谱分析。合适的单晶将用于结构细化。这些研究是对定义明确的样品进行多样化性质调查的先决条件。57Fe莫伯·鲍尔光谱学将被系统地用作研究各种材料的电子和磁性行为的局部技术。结合理论研究，主要目的将是阐明烟碱和烟碱氧化物的具体结构-性质-关系。

The proposed project has three key subjects, i. e. (i) improvement of the synthesis conditions for RETPnO materials and explorative synthesis of the systems RE–T–Pn–O and RE–T–Pn–O–Cl including structural investigations, (ii) studies of magnetic, electrical and specific heat data of selected RETPnO phases, and (iii) systematic 57Fe Mößbauer spectroscopic studies of iron containing RE(AE)T2Pn2 and RETPnO phases. The preparative part is indispensable for synthesis of high-quality, X-ray pure samples for physical property measurements. Diverse preparation techniques (arc-melting, induction melting, metal- or salt-flux synthesis) are available. All samples will be studied in detail by powder X-ray diffraction and metallography in combination with EDX. Suitable single crystals will be used for structure refinements. These studies are the prerequisite for the diverse property investigations on well defined samples. 57Fe Mößbauer spectroscopy will systematically be used as a local technique for studying the electronic and magnetic behaviour of the respective materials. Together with theoretical investigations the main goal will be the elucidation of concrete structure-property-relations for the pnictides and pnictide oxides.