Structure Characterization and Magnetic Behavior of NaNi4(PO4)3and KMn4(PO4)3

New sodium nickel and potassium manganese orthophosphates NaNi4(PO4)3(abbreviated asNNP) and KMn4(PO4)3(KMP) with tunnel structures have been synthesized. They crystallizes in the orthorhombic space group Pnmm witha=6.148(6) ?,b= 16.210(1) ?,c=9.479(4) ? for (NNP), anda=6.554(8) ?,b=16.04(9) ?,c=9.977(2) ? for (KMP). The structure is built up from trinuclear groups of edge-sharingMO6octahedra, giving rise to the [M3O11]chains running along the [100] direction. Both materials show antiferromagnetic interactions and exhibit spontaneous magnetization at low temperatures, which can be explained by a canting of spin arrangement, giving rise to a weak ferromagnetic component. This behavior can be interpreted on the basis of structural features and the characteristics of single-ion intercalations.