Study On The Primary Principle Of Electrochemistry And Magnetism Of Rare Earth Metal Oxide And Perovskite Materials

Ion transport properties of rare earth metal oxide materials has been the core content of solid oxide fuel cell research and perovskite structure of magnetic materials is also a strong correlation important research hotspot in the field of trivalent rare earth cerium ion can spontaneously induced base solid oxide fuel cells（SOFCs）the oxygen vacancy,so rare earth element doped CeO2 can enhance the conductivity of electrolyte ions.This paper use the method of first principles to Sm doped ceria（SDC）as the research object,Sm content on the ionic conductivity was calculated in the previous study,the influence of the Sm doping effects attributed to the Sm³⁺introduction to increase charge compensation space,binding energy between doped ions and oxygen vacancy for oxygen migration is also big in addition,the influence of oxygen enrichment and low oxygen conditions,SDC band structure was significantly different.Next,we studied the variety of rare earth elements and system（La、Nd、Sm、Gd、Tb、Dy and Er）doping Ce O₂ on the effect of ionic conduction in the solid oxide fuel cell,the results show that the rare earth element doped in addition to increase the oxygen vacancy also have many other effect For different doped ions and oxygen ion migration barrier is significantly different,at the same time,the migration barrier obviously depends on the size of the radius of the impurity ions.Experiment found on Gd and Sm is the optimal doping elements,but gave no reason,we through the internal formation of oxygen vacancies produced by thermal excitation can get Sm（Evac）calculation and Gd doped ceria system has the smallest Evac value,it is concluded that affect the screening on these elements is the key to thermal excitation caused by eigen space After that,we combine with experiment are calculated by some magnetic perovskite materials.A new oxide Ca Cr_0.5Fe_0.5O₃was prepared under high pressure and temperature conditions.CaCr_0.5Fe_0.5O₃ provides the first Cr⁵⁺perovskite system with octahedral coordination,opening a new avenue to explore novel transition-metal oxides with exotic charge states.CaFe_1-x-x Co_xO₃ single-crystal solid solution was prepared for the first time with the Co concentration x up to 0.3.The introduction of Co greatly suppresses the charge disproportion of Fe(2Fe⁴⁺→Fe³⁺+Fe⁵⁺)and sharply changes the magnetism and electrical transport properties.