Two dinuclear lanthanide (Ln) complexes, formulated as [phen2Ln2(HCOO)4(HCOO)2 2x(NO3)2x] (1, Ln = Gd and x = 0.52; 2, Ln = Er and x = 0.90; phen = 1,10-phenanthroline), were synthesized and characterized. They are isostructural. The dinuclear molecule consists of two Ln3+ bridged by four formate groups and chelated by phen and formate/nitrate ligands, and the Ln3+ possesses a coordination environment of distorted tri-capped trigonal prism of LnOTN2. Both compounds behave as paramag- nets between 2 and 300 K, but display two static field induced magnetic relaxation processes. One is slow and of spin-lattice type, and it results from the lifting of Kramer's degeneracy of the ground-states of both Gd3+ and Er3+, and the other is fast, and it might be spin-spin type.
The diverse magnetic properties of lanthanide-based magnetic molecular materials are introduced in the following organization.First,the general aspects of magnetic molecular materials and electronic states of lanthanide ions are introduced.Then the structures and magnetic properties are described and analyzed for molecules with one lanthanide ion,4f-4f,4f-3d and 4f-p magnetic coupling interactions.In each section,magnetic coupling,magnetic ordering and magnetic relaxation phenomenon are briefly reviewed using some examples.Finally,some possibilities of developing magnetic molecular materials containing lanthanide ions are discussed in the outlook part.
A comprehensive study on Raman spectroscopy with different excitation wavelengths, sample sizes, and sample shapes for optic phonons （OPs） and acoustic phonons （APs） in polar and non-polar nano-semiconductors has been performed. The study affirms that the finite size effect does not appear in the OPs of polar nano-semiconductors, while it exists in all other types of phonons. The absence of the FSE is confirmed to originate from the long-range FrShlieh interaction and the breaking of translation symmetry. The result indicates that the Raman spectra of OPs cannot be used as a method to characterize the scale and crystalline property of polar nano-semiconductors.
