Negative-chirality order in the S=12 kagome antiferromagnet CdCu3(OH)6

Abstract

Neutron diffraction and nuclear magnetic resonance (NMR) measurements have been used to analyze the magnetic structure in the S = 1 2 kagome antiferromagnet CdCu 3 (OH) 6 (NO 3 ) 2 • H 2 O. Below the magnetic ordering temperature T N 4 K, magnetic Bragg reflections at (101) and (100) were found in the neutron diffraction pattern, which suggests a q = 0 magnetic structure. Furthermore, the vector spin chirality for the q = 0 structure was successfully identified from the internal field direction obtained by the 14 N-NMR measurement, previous magnetization measurements, and magnetic symmetry analysis. Our findings point to a chirality-ordered magnetic structure with negative vector chirality and 100 anisotropy.