极端条件下凝聚态物质结构和性质的研究，为当今物理学和材料科学的重要研究领域，人们发现强磁场对凝聚态物性具有重要影响并呈现出许多新奇而有趣的物理现象，然而其微观机理尚不清楚。本课题将以亚铁磁结构的铁氧体为具体研究对象，旨在将磁场诱导技术引入前期样品制备过程，以结构表征和磁测量为主要手段，研究磁场诱导下材料的有序纳米结构、离子占位等一些基本物理问题，给出在外磁场下的材料制备过程与体系结构、磁性和相变的关系，研究诱导磁场、测量磁场与自旋/轨道耦合、自旋结构之间的相互影响，给出自旋结构分布特征和诱导/测量磁场的定量关系，并与自旋结构和相变的实验和理论研究相结合，重点给出结构变化、磁相变和离子占位随磁场变化的物理机制，为澄清强磁场诱导下相变过程的物理机制和开发铁氧体材料新功能提供重要的基础研究资料。

Structures and properties of condensed matter at extreme conditions have become one focus in modern physics and materials science. Although under high magnetic field many novel and interesting phenomena in physical properties have been discovered, the mechanism behind the phenomena is not unraveled satisfactorily. In this proposal, ferrimagnetic ferrites are fabricated by a magnetic-field-inducing technique. Some basic physical phenomena correlated with ordered nano-structures and ion distribution induced by magnetic field will be systemically investigated by means of structural characterization, magnetic measurements, and the related experimental methods. The correlation among fabricating process under magnetic field, structure, magnetism and phase transition will be systematically given. The conjunction of inducing field and measuring field, spin structure and spin-orbital coupling will be investigated, and the correlation of distribution of the spin structure and the magnetic field will be obtained. In conjunction with the experimental results and relative theoretical calculation in electronic structures and phase transition, the mechanism of structural transformation, magnetic transition and ion distribution as a function of the magnetic field, will be emphatically acquired. These results will be expected to provide some basic research data that are used to not only manifest the mechanism of magnetic-field-induced transition, but also develop new application of ferrite in functional materials.