Electron State Tailoring And New Inorganic Framework Of Rare Earth-transition Metal Complex Oxides

Chemistry is the science on constitution of matter and interaction rules inmolecules and atoms. It is the basis of exploring new matter states and creating newsubstance to study and reason the bonding relationship in any matters. Physical andchemical properties of any matter are determined by the key factors, such ascomposition, structure, valence states of elements, defects, as well as spin of electronsinside of any chemical compounds, which are also mostly concerned central interestsin solid chemistry research. By control and tailor these factors, many specialfunctional materials have been developed, such as superconductor, ferroelectricmaterial, giant magnetic resistance material, photoelectrical material and someanti-normal physical property metamaterials. Most of these materials are crystallizedin perovskite structure due to the physical and chemical specialty in this magicstructure, which draw a lot of attention of physical, chemical, and material scientist.The fundamental of these is electron state inside of each material, which refers tosome kind of constituted behavior of electronic structure in assembled atoms. Electronstate can be modulated by atoms, valence, molecular or crystal structure, composition,various kinds of defects, and spin of electrons, which determines the physical andchemical performance in materials.In this dissertation, we designed and prepared series of Cr-, Mn-, and Fe-basedrare-earth preovskite oxides by chemical composition, and crystal facets control basedon solid state inorganic chemistry principles.(1) Firstly, according to d-orbital itinerant and localized electron exchange theory and atomic scale p-n junctionphenomenon in La1-x-yCaxKyMnO3, we proposed a plan in preparation of newmaterials with three-order electronic states. Double transition metal perovskite oxideswith two-order electron states were prepared via hydrothermal method. It is difficultto prepared orderly arrangement of B-site atoms in similar sized transition metalcations, but we found that the degree of order was improved. This was also occurredin three-ordered electron states. Coordination effect was used in improve the degree ofCr, Mn, Fe order in SmCr1-x-yMnxFeyO3. However, no proper coordinates were founduntil now.(2) Crystal facets play important roles in the physical and chemicalproperties in many application fields, e.g. catalysis, sensor, and adsorption. Weproposed a facet modulating mechanism in perovskite oxides with non-sphericalelectric field cations. NH4+, which is decomposed from urea (CO(NH2)2), is the maincapping cation in many family perovskite oxide facets control, because of thecoordinate effect of NH4+with BO6octahedrons in the main framework of perovskites.This interaction retards the growth speeds of some facets in crystal growing process.Detailed factors in tailoring facets of LaFeO3were discussed. Series rare-earth ferrites,REFeO3, were tailored for high index crystal facets and the size effect of A-site cationson facet control was discussed. Crystal facets controlled growth must design andprepared according to the unit cell structure. Besides, this method was also used totailoring the shape and facet of La1-xSrxMnO3. Moreover, this crystal facet tailoringroute is also suitable for LaCrO3.(3) It is challenging to find and prepared newinorganic solid state structures because of the atom structure and its limitedcorresponding bonding relations. By diminishing alkalinity in perovskite oxidepreparation in hydrothermal process, we find a new3-dimensional frameworkstructure, which is rarely reported cationic in the host framework. Cl-was locatedinside of the host lattice to balance the charge. There are at least30compounds adoptthis structure. And it could be exchanged with other anions, and also worked asabsorbent, as well as luminescent material. Rare earth elements, Eu，Gd，Tb，Dy，Ho，Er，Tm，Yb，Lu，Y, and transition metals, Mn，Fe，Co，Ni, Cu, can be substitutedin the main structure. In summary, this dissertation proposed two electron states control routes forperovskite oxides, i.e. composition and crystal facets tailor technique to prepare highindex crystal facets. A new family of inorganic3-dimensional cation frameworkstructure compounds was prepared, and at least30compounds were included in thisfamily. This dissertation not only provides modulating methods of electron states inrare-earth transition metal perovskite oxides, but also reports a new family inorganicframework material. The results here may be a reference for future electron statesresearch in metal oxide, especially for crystal facets growth and surface dependentchemical properties, and are fundamental to further pure3-dimensional inorganiccation framework studies.