Triangular antiferromagnetic order in the honeycomb layer lattice of ErCl3 K. W. Krämer, H. U. Güdel, P. Fischer, F. Fauth, M. T. Fernandez-Diaz and T. Hauß Eur. Phys. J. B, 18 1 (2000) 39-47 Published online: 15 November 2000 DOI: 10.1007/s100510070075