Jacobs, P. ; Houben, A. ; Senyshyn, A. ; Müller, P. ; Dronskowski, R.

2013-06-
Academic Press Orlando, Fla.

Abstract: The magnetic structure of Co(NCNH)2 has been studied by neutron diffraction data below 10 K using the SPODI and DNS instruments at FRM II, Munich. There is an intensity change in the (1 1 0) and (0 2 0) reflections around 4 K, to be attributed to the onset of a magnetic ordering of the Co2+ spins. Four different spin orientations have been evaluated on the basis of Rietveld refinements, comprising antiferromagnetic as well as ferromagnetic ordering along all three crystallographic axes. Both residual values and supplementary susceptibility measurements evidence that only a ferromagnetic ordering with all Co2+ spins parallel to the c axis is a suitable description of the low-temperature magnetic ground state of Co(NCNH)2. The deviation of the magnetic moment derived by the Rietveld refinement from the expectancy value may be explained either by an incomplete saturation of the moment at temperatures slightly below the Curie temperature or by a small Jahn–Teller distortion.

Keyword(s): Basic research (1st) ; Others (1st) ; Magnetism (2nd) ; Magnetism ; Structure

1. DNS
2. SPODI

1. DNS: Diffuse scattering neutron time of flight spectrometer (NL6S)
2. SPODI: High resolution powder diffractometer (SR8a)