2D层状焦磷酸锰髤[NH_4]_2[Mn_3(P_2O_7)_2(H_2O)_2]的结构和磁性研究

由于具有开放骨架的金属磷酸盐在催化、吸附、主客体组装以及光学、磁学等方面的应用1~3],因此合成具有开放骨架的金属磷酸盐一直吸引着人们的广泛关注。自从1982年美国联合碳化公司(U.C.C.)开发出系列磷酸铝分子筛AlPO4鄄n4]以来,大量具有开放骨架的金属磷酸盐(金属=Ga,In,F

Structure and Magnetic Properties of a Two-dimensional Layered Manganese(II) Pyrophosphate [NH_4]_2[Mn_3(P_2O_7)_2(H_2O)_2]

A two-dimensional layered manganese(II) pyrophosphate, 2Mn3(P2O7)2(H2O)2] (1), has been synthesized hydrothermally. Its structure is determined by single-crystal X-ray diffraction analysis. Its structure is built up by MnO6 octahedra and P2O7 units, with ammonium NH4 cations residing in the interlayer regions. The manganese pyrophosphate layer consists of infinite chains of cis and trans edge sharing MnO6 octahedra linked by P2O7 units. Magnetic susceptibility measurements show that this compound exhibits ferrimagnetic-like ordering below 3.2 K. Further study shows that there are two possible superexchange pathways via the oxygen anions in Mn2 ions. Owing to the different bridging modes of O2-, the competition between ferromagnetic interactions and antiferromagnetic interactions in Mn2 ions results in the ferrimagnetic behavior of 1.