Doping dependence of spin-lattice coupling and two-dimensional ordering in multiferroic hexagonal Y1−xLuxMnO3 (0 x 1)

Junghwan Park,1,2,3 Seongsu Lee,2,* Misun Kang,2 Kwang-Hyun Jang,2 Changhee Lee,4 S. V. Streltsov,5,6 V. V. Mazurenko,6 M. V. Valentyuk,6 J. E. Medvedeva,7 T. Kamiyama,8 and J.-G. Park1,2,3,9,† 1Center for Strongly Correlated Materials Research, Seoul National University, Seoul 151-742, Korea 2Department of Physics, Sungkyunkwan University, Suwon 440-746, Korea 3Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Korea 4Neutron Science Division, Korea Atomic Energy Research Institute, Daejon 305-600, Korea 5Institute of Metal Physics, S. Kovalevskoy Street 18, 620041 Ekaterinburg GSP-170, Russia 6Ural State Technical University, Mira Street 19, 620002 Ekaterinburg, Russia 7Missouri University of Science and Technology, 1315 N. Pine Street, Rolla, Missouri 65409, USA 8Institute of Materials Structure Science, KEK, Tsukuba 305-0801, Japan 9Department of Physics & Astronomy, Seoul National University, Seoul 151-742, Korea Received 4 February 2010; revised manuscript received 26 July 2010; published 26 August 2010