Two isotypic diphosphates LiM2H3(P2O7)2 (M=Ni, Co) containing ferromagnetic zigzag MO6 chains

✍ Scribed by Tao Yang; Sihai Yang; Fuhui Liao; Jianhua Lin

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 727 KB
• Volume: 181
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2008.03.006

✦ Synopsis

Two new isotypic phosphates LiNi 2 H 3 (P 2 O 7 ) 2 (1) and LiCo 2 H 3 (P 2 O 7 ) 2 (2) have been hydrothermally synthesized and structurally characterized by the single-crystal X-ray diffraction technique. They crystallize in the monoclinic space group C2/c with the lattice:

The transition metal atoms are octahedrally coordinated, whereas the lithium and phosphorus atoms are all tetrahedrally coordinated. As the lithium-induced derivatives of MH 2 P 2 O 7 (M ¼ Ni, Co), 1 and 2 possess the same structure with MH 2 P 2 O 7 in terms of topology, comprising the MO 6 zigzag chains and P 2 O 7 as the interchain groups. The magnetisms of 1 and 2 could be interpreted by adopting a quasi-one-dimensional (1D) zigzag chain model as that in their parent compounds: both 1 and 2 have ferromagnetic (FM) NiO 6 /CoO 6 chains; 1 shows a FM cluster glass behavior at low temperatures, which is originated from the possible antiferromagnetic (AFM) next-nearest-neighbour intrachain interactions; 2 shows a AFM ordering at T N ¼ 2.6 K and a metamagnetic transition at H C ¼ 4.2 kOe at 1.8 K.