【摘要】 利用嵌入反应合成了有机 无机嵌入化合物Fe0 95PS3(MV) 0 1 1 (MV为 1,1′ 二甲基 4 ,4′ 联吡啶阳离子 ) ,对其结构和磁性进行了研究 .x射线衍射数据表明 ,此嵌入化合物的晶体结构仍为单斜晶系 ,空间群为C2 m ,晶胞参数a=0 879nm ,b=0 94 4nm ,c=1 0 70nm ,β =114 76°.相对于纯FePS3,层间距离增大 0 33nm .磁化率研究表明 ,从室温降到 4 2K过程中 ,此化合物经历了两级磁相变 .在居里温度TC =84K以下发生铁磁相变 ,奈尔温度TN =2 6K以下为反铁磁相变 .12— 30 0K变温M ssbauer谱研究证实 ,此化合物存在三个高自旋二价铁的位置 ,表明在嵌入反应过程中有电荷从客体分子转移到主体晶格中Fe—S的e g 反键轨道上 ,并有部分铁离子从晶格中脱出 ,从而在主体晶格中产生金属阳离子空位 .铁磁性是由于自旋倾斜所致 ,而极低温度下自旋倾斜消失 ,又表现为反铁磁性 .更多还原

【Abstract】 The intercalation compound Fe 0.95PS 3(MV) 0.11 (MV is the methylvi ologen cation) h as been prepared. Its crystal structure and magnetism have been investigated by x-ray diffraction (XRD), susceptibility measurements and Mssbauer experiments . Its XRD pattern can be indexed in a monoclinic unit cell with a=0.879?nm, b=0.944?nm, c=1.070?nm, β=114.76°. The distance between layer s of this intercal ation compound is increased by 0.33?nm compared with that of FePS 3. The data of susceptibility show that second-order magnetic phase transitions have occu rred when the temperature changed from 300?K down to 4.2?K. A ferromagnetic phase tran sition occurred below T C=84?K. An antiferromagnetic phase transition oc curred below T N=26?K. The results of Mssbauer spectra taken in the te mperature range of 12 to 300?K indicate that there are three kinds of divalent ions with their high spin states , which imply a charge transfer from guest to the Fe—S e * g antibonding orbi tals of the FePS 3 host lattice, and some ions have been released from the FePS 3 h ost lattice and then some vacancies have been formed. The ferromagnetism originates f rom a canting of the spins of Fe 2+, whereas the antiferromagnetism occurre d when the canting of the spins of Fe 2+ have been modified at the lowest tem peratures.更多还原