Structural and magnetic behavior of a quasi-1D antiferromagnetic chain compound Cu(NCS)2(PYZ)

Synchrotron X-ray diffraction (XRD) and neutron powder diffraction (NPD) were used to determine the structure of Cu(NCS)(2)(PYZ) (pyz = pyrazine = C4N2H4), which consists of a stacking of Cu-pyz-Cu chains. While NPD measurements showed no evidence of long-range magnetic ordering, the temperature dependence of the magnetic susceptibility and magnetization suggests that the system can be adequately described on the local scale as a spin-1/2 antiferromagnet (AFM) chain with an intrachain exchange interaction J/k(B) = -8 K (similar to0.7 meV). Comparison of isothermal magnetization data acquired up to 30 T at 1.6 K to a linear chain model shows excellent agreement, making this material a nearly ideal example of an isotropic Heisenberg AFM chain. (C) 2003 Elsevier Science Ltd. All rights reserved.