铁基超导材料表现出丰富的轨道、磁性和超导的性质，导致目前对结构、磁性和超导机理，以及超导配对对称性等方面在理论和实验上都有很大的争议。在实验的角度，如何从铁基材料中电子的轨道、磁性和电性的关联性质出发，细致而深入地研究铁基超导材料是目前的重点。在前期核磁共振工作的基础上，我们重点计划通过系统地研究晶体结构、维度、电子过掺杂、高压效应等，揭示材料本征的相图、不同自旋涨落模式、超导配对对称性，最终促进对不同铁基材料中电子关联效应的认识等，促进对非常规超导材料的磁性和超导电性的理论认识。

The iron-based superconductors have demonstrated rich properties in the orbital, magnetism and superconductivity. This has caused a lot of controversy in the mechanism of the structure transition, magnetic transition, and the superconductivity, and as well in the pairing symmetry of superconductivity. Experimentally, it is important to realize that the electron correlation effects among the orbitals, magnetism and the electrical properties are crucial, which needs more careful and detailed studies. Based on our previous NMR studies, we plan to study systemtically on the crystalline structure,dimensionality, overdoping, and high pressure effect, in order to disclose the the intric phase diagram, different spin fluctuations, and the pairing symmetries. Our goal is to improve the understandings of the electron correlation effect in the iron-based superconductors, and to improve our understanding of the mechanism of antiferrmagnetism and superconductvitiy in the unconventional superconductivity.