title: Experimental percolation studies of two-dimensional honeycomb lattice: Li2Mn1-xTixO3.
abstract: Li2MnO3 with a S = 3/2 two-dimensional Mn honeycomb lattice has a Neel-type antiferromagnetic transition at TN = 36 K with a broad maximum in magnetic susceptibility at TM = 48 K. We have investigated site percolation effects by replacing Mn with nonmagnetic Ti, and completed a full phase diagram of Li2Mn1-xTixO3 solid solution systems to find that antiferromagnetic transition is continuously suppressed without a clear sign of changes in the Neel-type antiferromagnetic structure. The magnetic ordering eventually disappears at a critical concentration of xc = 0.7. This experimental observation is consistent with percolation theories for a honeycomb lattice when one considers up to 3rd nearest-neighbor interactions. This study highlights the importance of interaction beyond nearest neighbors even for the Mn element with relative localized 3d electrons in the honeycomb lattice.
authors.affiliation: Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-747, Korea. Center for Strongly Correlated Materials Research, Seoul National University, Seoul 151-742, Korea. Department of Physics, SungKyunKwan University, Suwon 440-746, Korea.
authors.forename: Sanghyun
authors.initials: S
authors.lastname: Lee
authors.forename: Junghwan
authors.initials: J
authors.lastname: Park
authors.forename: Jiyeon
authors.initials: J
authors.lastname: Kim
authors.forename: Kun-Pyo
authors.initials: KP
authors.lastname: Hong
authors.forename: Youngmi
authors.initials: Y
authors.lastname: Song
authors.forename: Je-Geun
authors.initials: JG
authors.lastname: Park