In EuCo2P2, 4f electron spins of Eu2+ ions order antiferromagnetically below a Néel temperature. The magnetic structure below was reported to be helical with the helix axis along the c-axis from the neutron diffraction study. We report the results of 153Eu, 59Co and 31P nuclear magnetic resonance (NMR) measurements on EuCo2P2 using a single crystal and a powdered sample. In the antiferromagnetic (AFM) state, we succeeded in observing 153Eu, 59Co and 31P NMR spectra in zero magnetic field. The sharp 153Eu zero field NMR (ZF NMR) lines indicate homogeneous Eu ordered moment. The 59Co and 31P ZF NMR spectra showed an asymmetric spectral shape, indicating a distribution of the internal magnetic induction at each nuclear position. The AFM propagation vector k characterizing the helical AFM state can be determined from the internal magnetic induction at Co site. We have determined the model-independent value of the AFM propagation vector k distributed from (0, 0, 0.86)2π

We report 119 Sn NMR studies on LaRu 2 Sn 2 Zn 18. LaRu 2 Sn 2 Zn 18 was synthesized by replacing a part of Zn of LaRu 2 Zn 20 with Sn. To clarify the substitution site of Sn in three batches of samples grown under different conditions, 119 Sn NMR spectra of the powder samples were measured. A significant difference in the NMR spectral shape and linewidth was observed depending on the growing conditions. We also measured the NMR spectrum of single-crystal and found that Sn was substituted only at the 16c site in the best sample. Besides, the analysis of the spectral shape considering the local symmetry around the Sn nucleus suggested the possibility of slight strain in the crystal, which might be due to the incomplete Sn substitution at the 16c site.