Dzyaloshinsky-Moriya Anisotropy in the Spin-1/2 Kagom\'e Compound   ZnCu$_{3}$(OH)$_{6}$Cl$_{2}$
  We report the determination of the Dzyaloshinsky-Moriya interaction, the dominant magnetic anisotropy term in the \kagome spin-1/2 compound {\herbert}. Based on the analysis of the high-temperature electron spin resonance (ESR) spectra, we find its main component $|D_z|=15(1)$ K to be perpendicular to the \kagome planes. Through the temperature dependent ESR line-width we observe a building up of nearest-neighbor spin-spin correlations below $\sim$150 K. 
A. Zorko, S. Nellutla, J. van Tol, L. C. Brunel, F. Bert, F. Duc, J.   C. Trombe, M. A. de Vries, A. Harrison, P. Mendels