Thermodynamic and single-ion properties of Tb3+ within the collective paramagnetic-spin liquid state of the frustrated pyrochlore antiferromagnet Tb2Ti2O7

By Michel J. P. Gingras, B. C. D. Hertog, M. Faucher, J. Gardner, S. Dunsiger, L. Chang, B. Gaulin, N. P. Raju, J. Greedan. 2000

187 citations recorded by the source corpus.

In a recent letter [Phys. Rev. Lett. {\bf 82}, 1012 (1999)] it was found that the Tb$^{3+}$ magnetic moments in the Tb$_2$Ti$_2$O$_7$ pyrochlore lattice of corner-sharing tetrahedra remain in a {\it collective paramagnetic} state down to 70mK. In this paper we present results from d.c. magnetic susceptibility, specific heat data, inelastic neutron scattering measurements, and crystal field calculations that strongly suggest that (1) the Tb$^{3+}$ ions in Tb$_2$Ti$_2$O$_7$ possess a moment of approximatively 5$\mu_{\rm B}$, and (2) the ground state $g-$tensor is extremely anisotropic below a temperature of $O(10^0)$K, with Ising-like Tb$^{3+}$ magnetic moments confined to point along a local cubic $ $ diagonal (e.g. towards the middle of the tetrahedron). Such a very large easy-axis Ising like anisotropy along a $ $ direction dramatically reduces the frustration otherwise present in a Heisenberg pyrochlore antiferromagnet. The results presented herein underpin the conceptual difficulty in understanding the microscopic mechanism(s) responsible for Tb$_2$Ti$_2$O$_7$ failing to develop long-range order at a temperature of the order of the paramagnetic Curie-Weiss temperature $\theta_{\rm CW} \approx -10^1$K. We suggest that dipolar interactions and extra perturbative exchange coupling(s)beyond nearest-neighbors may be responsible for the lack of ordering of Tb$_2$Ti$_2$O$_7$.

Subfields: Condensed Matter Physics, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/0cef6761080b69c1c07cfd50ee63b297f2ced0e2

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In Condensed Matter Physics

1. Michel J. P. Gingras
2. J. S. Gardner
3. J. Greedan

In Electronic, Optical and Magnetic Materials

1. Michel J. P. Gingras
2. J. S. Gardner
3. J. Greedan

Citations in the corpus

• Magnetic Pyrochlore Oxides (2009, background): “However, consideration of the single-ion crystal field ground state doublet of Tb3+ in Tb2Ti2O7 strongly suggests that, in absence of exchange and dipolar interactions, bare Tb3+ should be considered as an effective Ising spin (Gingras et al., 2000; Rosenkranz et al., 2000).”