【摘要】 利用熔融KOH和Co3O4在较低温度(480℃)下反应制备出K0.36CoO2,然后用高锰酸钾溶液和饱和的过硫酸钾溶液进行氧化处理.氧化的同时伴随有水分子嵌入.K0.36CoO2用高锰酸钾和过硫酸钾溶液处理后分别得到K0.12CoO2.0.8H2O和K0.16CoO2.0.6H2O.这两种化合物都属于六角晶系,表现出金属行为,脱水后主相变为正交结构并且呈现出半导体特性.K0.16CoO2.0.6H2O在56K附近可能存在自旋玻璃转变行为或其他涨落.随着钾含量的减少和水含量的增多,样品的自旋玻璃行为受到抑制或发生磁性相分离.样品K0.12CoO2.0.8H2O在零场冷却和有场冷却曲线上的分叉现象基本上消失.还讨论了产生KxCoO2与NaxCoO2体系结构和物性差别的原因.更多还原

【Abstract】 Layered potassium cobaltate K 0.36 CoO₂ has been successfully synthesized from KOH fluxes at 480?℃. The K 0.36 CoO₂ sample can be oxidized and intercalated with water by treatment in KMnO₄ and K₂S₂O₈ solutions. K 0.12 CoO₂·0.8H₂O and K 0.16 CoO₂·0.6H₂O have been obtained after the KMnO₄ and K₂S₂O₈ treatment, respectively. The diffraction peaks of K 0.12 CoO₂·0.8H₂O and K 0.16 CoO₂·0.6H₂O can be well indexed by a hexagonal cell similar to the monolayer hydrate Na_xCoO₂·yH₂O. After dehydration, the major phases have an orthorhombic structure similar to Na 0.5 CoO₂ and show semiconductor behavior. Both K 0.12 CoO₂·0.8H₂O and K 0.16 CoO₂·0.6H₂O are primarily paramagnetic and show metallic behavior. K 0.16 CoO₂·0.6H₂O has a spin-glass-like transition or other magnetic fluctuations around 56?K. The spin-glass-like transition or the regions of magnetic phase separation are reduced in K 0.12 CoO₂·0.8H₂O due to the increasing of the intercalated water. We also discussed similarities and differences between the structural and physical properties of K_xCoO₂ and Na_xCoO₂.更多还原