Our neutron scattering study revealed that NpNiGa5 has a canted structure with the antiferromagnetic (AFM) component along [1 1 0] with q = ( frac(1, 2) frac(1, 2) frac(1, 2) ) below 18 K, superposed on a ferromagnetic (FM) component along the c-axis. A simple FM order remains stable with elevating temperature ( 18 K < T < 30 K) or applying field ( μ0 H > 8 T) along [1 1 0]. The large difference in the magnetic moment for these two structures indicates that the transition at TN = 18 K is attributed to the 5f electronic transition between the low-moment FM state and high-moment state accompanying the in-plane AFM component perpendicular to the quantization c-axis. It can be qualitatively understood by a localized 5f model with competing interactions, while the 5f electrons are believed to be itinerant from the partial quenching of the orbital contribution in the magnetic form factor.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering