Nuclear quadrupole resonance in two sublattice 2-D antiferromagnetic cuprate Sr2Cu3O4Cl2

Abstract The results of the first nuclear quadrupole resonance (NQR) investigations on the 63,65 Cu and the 35 Cl nuclei in oxychloride Sr 2 Cu 3 O 4 Cl 2 are presented. The copper spectrum above T N2 =40 K is attributed to 63,65 Cu Zeeman spectrum of Cu1 nuclei in the local in-plane magnetic field of 93 kOe perturbed by quadrupole splitting in the first order. Below T N2 NQR spectrum is essentially changed and the low-frequency part appears, which can be assigned to the ordering of the Cu2 magnetic subsystem. The 35 Cl NQR spectra reveals the existence of the local magnetic field of 210 Oe on Cl site pointing to the ferromagnetic alignment of the Cu1 magnetic moments along the c -axis.