title: Doping effects on trimerization and magnetoelectric coupling of single crystal multiferroic (Y,Lu)MnO3.
abstract: Hexagonal RMnO3is a multiferroic compound with a giant spin-lattice coupling at an antiferromagnetic transition temperature, Lee et al (2008 Nature 451 805). Despite extensive studies over the past two decades, the origin and underlying microscopic mechanism of strong spin-lattice coupling remain very much elusive. In this study, we have tried to address this problem by measuring the thermal expansion and dielectric constant of doped single crystals Y1-xLuxMnO3where x  =  0, 0.25, 0.5, 0.75, and 1.0. From these measurements, we confirm that there is a progressive change in the physical properties with doping. At the same time, all our samples exhibit clear anomalies at TN, even in the samples where x  =  0.5 and 0.75. This is opposed to some earlier ideas, which suggests an unusual doping dependence of the anomaly. Our work reveals yet another interesting facet of the spin-lattice coupling issue in hexagonal RMnO3.
authors.affiliation: Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea. Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea.
authors.forename: Seongil
authors.initials: S
authors.lastname: Choi
authors.forename: Hasung
authors.initials: H
authors.lastname: Sim
authors.forename: Soonmin
authors.initials: S
authors.lastname: Kang
authors.forename: Ki-Young
authors.initials: KY
authors.lastname: Choi
authors.forename: Je-Geun
authors.initials: JG
authors.lastname: Park