GeFe2O4晶体的基态能级和零场分裂参量

GeFe₂O₄是一种单晶化合物，考虑到由3个〈111〉方向之一的一个 轴，从一个中心位置 到另一个中心位置之间，以Fe²⁺离子为中心离子和O^2-为配体构 成了三角（C 3v）对称体系.利用不可约张量理论，建立了3d⁴/3d⁶离子三角（C3 v）对称的晶体场和 自旋相互作用哈密顿矩阵，因此，由完全对角化的晶体场和自旋-轨道相互作用哈密顿矩阵 和电子顺磁共振理论公式求出单晶GeFe₂O₄中Fe²⁺离子 的电子顺磁共振零场分 裂参量D和F-a.并研究了自旋三重态对电子顺磁共振（EPR）零场分裂的贡献.结果显示自旋 三重态对基态零场分裂的贡献是较强的，理论计算结果与实验值相符. 关键词： 自旋三重态 晶体场 低自旋态 高自旋态 零场分裂

Ground-state energy and zero-field splitting parameters in GeFe2O4 crystal

GeFe₂O₄ is a spinel-type compound in which the neighborhoo d of a Fe²⁺ ion has a trigonal symmetry with respect to an axis which is parallel to one of the three 〈111〉 direction,and varies from site to site . The crystal-field and spin-orbit complete Hamiltonian matrix of 3d⁴/3d⁶ ions ha ve been establishe d by irreducible representation method, The zero-field splitting parameters D an d F-a of Fe²⁺ ions in GeFe₂O₄ crystal are prese nted by using the cryst al-field and spin-orbit interaction complete diagonalizing Hamiltonian matrix wi th the theory of electron paramagnetic resonance; at the same time, the contribu tions to zero-field splitting from spin-triplet state have been studied. The res ults show that the contributions to zero-field splitting from spin-triplet state are important and strong. The calculated results are in good agreement with the experimental data.