Absence of long-range magnetic ordering in the pyrochlore compound Er2Sn2O7

Department of Chemistry, University of Winnipeg, Winnipeg, MB, R3B 2E9, Canada.
Journal of Physics Condensed Matter (Impact Factor: 2.35). 09/2011; 23(38):382201. DOI: 10.1088/0953-8984/23/38/382201
Source: PubMed


The low temperature behaviour of powder Er2Sn2O7 samples has been studied by magnetic susceptibility, heat capacity, and neutron scattering experiments. We report here the absence of magnetic ordering down to 100 mK. Anomalies in the heat capacity can be accounted for through an analysis of the crystal field spectrum observed by inelastic neutron scattering spectroscopy. These new measurements on Er2Sn2O7 suggest a new lower bound for the frustration index of f = |Θ(CW)|/T(N) = 14/0.1 = 140, placing this compound into a highly frustrated regime.

Download full-text


Available from: C. R. Wiebe, Dec 16, 2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: The magnetic properties of Ho(2)Sn(2)O(7) have been investigated and compared to other spin ice compounds. Although the lattice has expanded by 3% relative to the better studied Ho(2)Ti(2)O(7) spin ice, no significant changes were observed in the high temperature properties, T is more or approximately equal to 20 K. As the temperature is lowered and correlations develop, Ho(2)Sn(2)O(7) enters its quantum phase at a slightly higher temperature than Ho(2)Ti(2)O(7) and is more antiferromagnetic in character. Below 80 K a weak inelastic mode associated with the holmium nuclear spin system has been measured. The hyperfine field at the holmium nucleus was found to be ≈700 T.
    No preview · Article · Feb 2012 · Journal of Physics Condensed Matter
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Solids can be classified into two general categories: (1) crystalline solids, which have a well-defined unit cell that translates in space, and (2) amorphous solids, or glasses, which are characterized by a lack of such long-ranged order. Such classification has been extended to magnetic systems, where spins residing on a lattice typically undergo long-ranged ordering below a transition temperature set by the magnitude of the relevant exchange interactions. However, frozen random spins on a lattice may fail to develop long-ranged order resulting in a magnetic, or spin, glass. The Hamiltonians for these spin glasses have two simple ingredients - explicit random chemical disorder and frustration. For years, physicists have searched for a material link between structural and spin glasses. While such systems have proved challenging to find, one example is Y2Mo2O7 - a solid with no explicit random disorder that displays spin glass behaviour. The nature of the spin-freezing, particularly whether or not it is intrinsic, has been a matter of debate for over three decades. Here, we report the first single crystal growth of this material. Through physical property measurements, scattering experiments, and theoretical modelling, we offer novel insight into the Y2Mo2O7 problem: for this unconventional spin glass, orbital effects should not be ignored.
    Full-text · Article · May 2013 · Physical Review B
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: \ersn\, is considered, together with \erti, as a realization of the XY antiferromagnet on the pyrochlore lattice. We present magnetization measurements confirming that \ersn\, does not order down to 100 mK but exhibits a freezing below 200 mK. Our neutron scattering experiments evidence the strong XY character of the \er moment and point out the existence of short range correlations in which the magnetic moments are in peculiar configurations, the Palmer-Chalker states, predicted theoretically for an XY pyrochlore antiferromagnet with dipolar interactions. Our estimation of the \ersn\, parameters confirm the role of the latter interactions on top of relatively weak and isotropic exchange couplings.
    Full-text · Article · Jul 2013 · Physical Review B
Show more