Investigation of Chemical Bond Properties and Mossbauer Isomer Shifts in R-Type Hexagonal Barium Ferrites
R型六方铁氧体化学键性质和穆斯堡尔谱位移研究

By using the average band-gap model, chemical bond properties of BaTi2Fe4O11 and BaSn2Fe4O11 were studied. Mossbauer isomer shifts of 57Fe, 119Sn in BaTi2Fe4O11 and BaSn2Fe4O11 were calculated by using the chemical surrounding factor, h, defined by covalency and electronic polarizability. The charge state and site of 57Fe and 119Sn were also represented. The calculated results show that the covalency of 2a, 4f, 4e, 6g sites in BaTi2Fe4O11 is 0.062,0.354,0.309,0.361 respectively and one of 2a, 4f, 4e, 6g sites in BaSn2Fe4O11 is 0.062, 0.353, 0.183, 0.255 respectively.