铁掺杂PrBa_2Cu_3O_7的化学键性质和Mssbauer谱研究

Chemical bond properties of PrBa_2Cu_3O_7 and its Mssbauer spectroscopy

利用电介质的平均能带模型计算了PrBa2 Cu3O7的化学键参数 ,得到Cu(1 )—O键的平均共价性为 0 .4 1 ,Cu(2 )—O键的平均共价性为 0 .2 8.应用由共价性和极化率定义的化学环境因子计算了5 7Fe在PrBa2 Cu3O7中的M ssbauer同质异能位移 ,确定了5 7Fe在PrBa2 Cu3O7中的价态和占位情况 .

By using the average band-gap model, the chemical bond properties of PrBa 2Cu 3O 7 were calculated. The calculated covalencies for Cu(1)—O and Cu(2)—O bond in PrBa 2Cu 3O 7 compounds are 0.41 and 0.28 respectively. Mssbauer isomer shifts of 57 Fe doped in PrBa 2Cu 3O 7- x were calculated by using the chemical surrounding factor, h e, defined by covalency and electronic polarizability. Four valences state and three valence iron sites were identified in 57 Fe doped PrBa 2Cu 3O 7- x superconductors.