Experimental percolation studies of two-dimensional honeycomb lattice: Li₂Mn_1–xTi_xO₃

Abstract

Li 2 MnO 3 with a S=3/2 two-dimensional Mn honeycomb lattice has a Neel-type antiferromagnetic transition at T N =36 K with a broad maximum in the magnetic susceptibility at T M =48 K. We have investigated site percolation effects by replacing Mn with nonmagnetic Ti, and completed a full phase diagram of Li 2 Mn 1-x Ti x O 3 solid solution systems to find that the antiferromagnetic transition is suppressed continuously without a clear sign of changes in the Neel-type antiferromagnetic structure. The magnetic ordering eventually disappears at a critical concentration of x c =0.7. This experimental observation is consistent with percolation theories for a honeycomb lattice when one considers up to 3 rd nearest-neighbor interactions. This study highlights the importance of interaction beyond nearest neighbors even for Mn element with relative localized 3d electrons in the honeycomb lattice.

Rapid Suppression of Quantum Many-Body Magnetic Exciton in Doped van der Waals Antiferromagnet (Ni,Cd)PS3

“…The paramagnetic-to-antiferromagnetic transition temperature (in Figure b) almost linearly decreases upon increasing dopant concentration, changing by about 24% from x = 0 to 0.1. The doping-induced drop in the transition temperature agrees with the percolation theory . Additionally, the Curie tail or susceptibility upturn at low temperatures gradually increases due to the disordered spins near the nonmagnetic Cd atoms embedded in the background of the original collinear-ordered states.…”

“…The doping-induced drop in the transition temperature agrees with the percolation theory. 12 Additionally, the Curie tail or susceptibility upturn at low temperatures gradually increases due to the disordered spins near the nonmagnetic Cd atoms embedded in the background of the original collinear-ordered states. As aforementioned, the extremely narrow and high-intensity peak is key evidence for the coherent phenomena from the simultaneous dipole transition of the local NiS 6 clusters.…”

Magnetic dilution of a honeycomb lattice XY magnet CoTiO3

“…At the NN honeycomb lattice percolation threshold, a shift in the slope of the transition temperature was observed, which was attributed to a loss of dependence on the NN interactions. In their study of replacing Mn with Ti in Li 2 MnO 3 , Lee et al reported that the percolation threshold in this system is 0.7, suggesting that there are contributions of up to third nearest neighbors [14]. There have been a few theoretical studies in this direction as well.…”

“…Magnetic dilution has been studied in MnPS 3 as well as Li 2 MnO 3 . Both these compounds are made up of honeycomb layers, in which spins are coupled antiferromagnetically within the plane [13,14]. In their study of diluting MnPS 3 by replacing Mn with Zn, Goossens et al reported that the percolation threshold of the material was 0.55 instead of the 0.3 expected for a NN honeycomb lattice [13].…”

Infrared probe of spin-phonon coupling in antiferromagnetic honeycomb lattice compound Li2MnO3

“…A quantum Monte Carlo study also suggested that a quantum spin liquid state might emerge if the honeycomb system was located in the intermediate correlation regime where the carriers are partially localized [11]. A percolation study of Li 2 Mn 1−x Ti x O 3 indicated that the further-neighbor interactions were not negligible: the evolution of the magnetic ground state can be described well when one considers up to the third nearest-neighbor interactions [12]. The release of a significant amount of magnetic entropy above T N , which is usually seen in systems with strong frustration, further suggests the presence of magnetic frustration in Li 2 MnO 3 [9].…”