Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2010-03-04
Physics
Condensed Matter
Strongly Correlated Electrons
This paper has been withdrawn by the author and replaced by arXiv1006.0437
Scientific paper
We have synthesized the novel material Na_2IrO_3 and studied its structure, transport, magnetic, and thermal properties using powder x-ray diffraction (PXRD), electrical resistivity, isothermal magnetization M versus magnetic field H, static \chi and dynamic \chi_ac magnetic susceptibility versus temperature T, and heat capacity C versus T measurements. Na_2IrO_3 crystallizes in the monoclinic C2/c (No. 15) structure which is made up of Na and NaIr_2O_6 layers alternately stacked along the c axis. From a Rietveld refinement of the PXRD pattern we identify atomic disorder arising from a mixing of Ir and Na sites within the NaIr_2O_6 layers. The \chi data in H = 1 T shows Curie-Weiss behavior at high T > 100 K with an effective moment \mu_eff = 1.82(1) \mu_B indicating an effective spin S_eff = 1/2 on the Ir^{4+} moments. A Weiss temperature \theta = - 62(1) K indicates substantial antiferromagnetic interactions between these S_eff = 1/2, Ir^{4+} moments. The \chi data in low field show a sharp cusp at T_g = 5.5 K and there is a bifurcation between zero-field-cooled (ZFC) and field-cooled (FC) data below this T. The \chi_ac data also show a sharp cusp at T_g = 5.5 K at a frequency f = 1 Hz which moves to higher temperatures with increasing f. We did not observe any anomaly at T_g in our C measurements and only a broad shoulder was observed at a much higher T = 12 K. Our results indicate that in Na_2IrO_3, a spin-glass like state occurs below the freezing temperature T_g = 5.5 K and this freezing most likely arises either from structural disorder or geometrical magnetic frustration.
Gegenwart Philip
Singh Yogesh
No associations
LandOfFree
Spin glass like behavior in the novel layered material Na_2IrO_3 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Spin glass like behavior in the novel layered material Na_2IrO_3, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spin glass like behavior in the novel layered material Na_2IrO_3 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-559845