Dresden 2014 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 79: Correlated Electrons - Poster Session
TT 79.41: Poster
Wednesday, April 2, 2014, 15:00–19:00, P2
NMR as a local probe for 5d and 4d magnetism in honeycomb lattices A2TO3; (A=Na,Li; T=Ir,Rh) — •Panchanana Khuntia1, Mayukh Majumder1, Soham Manni2, Philipp Gegenwart2, and Michael Baenitz1 — 1Max Planck Institute for Chemical Physics of Solids, Dresden, Germany — 2I. Physikalisches Institut, Georg-August-Universitaet Goettingen, Goettingen, Germany
Recently, 5d iridates like the honeycomb lattices (Na,Li)2IrO3 and 4d analog Li2RhO3 display unconventioal magnetic properties which are driven by spin orbit coupling and frustration. There is a cross-over from Néel (zig-zag) type magnetic ordering to a spin-liquid state in the Heisenberg-Kitaev model. We report temperature (T) and field (H) dependent NMR study on Na2IrO3, Li2IrO3, and Li2RhO3. 23Na NMR in Na2IrO3 enable us to disentangle three Na sites and deduce the magnetic order parameter.The T and H dependent NMR spectra and spin lattice relaxation rate (SLR) reveal that Na2IrO3 and Li2IrO3 are magnetically ordered with TN = 15 K, additionally, Li2IrO3 exhibits features reminiscent of a spin-liquid.In Li2RhO3, magnetization and specific heat data exhibit no sign of long range ordering down to 0.3 K but a spin glass transition is observed at Tg=8 K. 7Li NMR line width and SLR in Li2RhO3, display signatures of spin correlation and emergence of slowing down of spin fluctuations on approaching the freezing temperature. The specific heat and SLR show power law behavior below Tg reflecting the persistence of low lying excitations pointing towards a spin liquid state.