The magnetic properties of a recently discovered metal-organic magnetic chain compound, [Co (bpdc) (H2 O)2] · H2 O, were investigated using measurements of magnetic susceptibility M (T) H, isothermal magnetization M (H), and heat capacity C (T). The room temperature crystal structure of [Co (bpdc) (H2 O)2] · H2 O is monoclinic, space group C2c, with lattice parameters a=6.950 Å, b=31.585 Å, c=6.226 Å, and Β=95.84°. The M (T) H data above 40 K were fit to Curie-Weiss law with an effective moment of 5.37 μB and a Curie-Weiss temperature of +26 K. A spontaneous antiferromagnetic ordering with a transition temperature of 5.5 K was observed in the low field M (T) H data. In addition, a metamagnetic transition at 500 G was found in M (H), measured at 2 K. The sizable anomaly observed in C (T) confirms the magnetic phase transition and the transition temperature. The total magnetic entropy removal at 5.5 K is 800 mJmol K. The nature of the magnetic properties is discussed in terms of the ferromagnetic intrachain exchange interaction between the Co(II) ions through the bridging hydrogen atoms along the magnetic chain and the antiferromagnetic Co-Co interchain coupling.
ASJC Scopus subject areas
- Physics and Astronomy(all)