Surface state on first-order ferroelectrics J. Osman, D. R. Tilley, R. Teh, Y. Ishibashi, M. N.A. Halif and K.-H. Chew Eur. Phys. J. B, 52 1 (2006) 143-150 Published online: 06 July 2006 DOI: 10.1140/epjb/e2006-00271-1