Magnetisation process in Er2Ti2O7 and Tb2Ti2O7 at very low temperature

Abstract

We present a model which accounts for the high field magnetisation at very low temperature in two pyrochlore frustrated systems, Er2Ti2O7 and Tb2Ti2O7. The two compounds present very different ground states: Er2Ti2O7, which has a planar crystal field anisotropy, is an antiferromagnet with T_N=1.2K, whereas Tb2Ti2O7 is expected to have Ising character and shows no magnetic ordering down to 0.05K, being thus labelled a ``spin liquid''. Our model is a mean field self-consistent calculation involving the 4 rare earth sites of a tetrahedron, the building unit of the pyrochlore lattice. It includes the full crystal field hamiltonian, the infinite range dipolar interaction and anisotropic nearest neighbour exchange described by a 3-component tensor. For Er2Ti2O7, we discuss the equivalence of our treatment of the exchange tensor, taken to be diagonal in a frame linked to a rare earth - rare earth bond, with the pseudo-spin hamiltonian recently developped for Kramers doublets in a pyrochlore lattice. In Tb2Ti2O7, an essential ingredient of our model is a symmetry breaking developping at very low temperature. We compare its prediction for the isothermal magnetisation with that of ``the quantum spin ice'' model.

References in corpus (7)

• Definitive Evidence for Order-by-Quantum-Disorder in Er2Ti2O7
• Quantum order by disorder and accidental soft mode Er2Ti2O7
• Rods of Neutron Scattering Intensity in Yb2Ti2O7: Compelling Evidence for Significant Anisotropic Exchange in a Magnetic Pyrochlore Oxide
• Understanding Paramagnetic Spin Correlations in the Spin-Liquid Pyrochlore Tb2Ti2O7
• Magnetic order, magnetic correlations and spin dynamics in the pyrochlore antiferromagnet Er2Ti2O7
• Energetic selection of ordered states in a model of the Er2Ti2O7 frustrated pyrochlore XY antiferromagnet
• Ising versus XY anisotropy in frustrated R${}_2$Ti${}_2$O${}_7$ compounds as seen by polarized neutrons

Cited by in corpus (17)

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• Living on the edge : ground-state selection in quantum spin-ice pyrochlores
• Experimental Insights into Ground State Selection of Quantum XY Pyrochlores
• Order by Disorder Spin Wave Gap in the XY Pyrochlore Magnet Er2Ti2O7
• Nature of finite-temperature transition in anisotropic pyrochlore Er2Ti2O7
• Order from structural disorder in $XY$ pyrochlore antiferromagnet $\mathrm{E}{\mathrm{r}}_2\mathrm{T}{\mathrm{i}}_2{\mathrm{O}}_7$
• Frustrated Magnetism in Fluoride and Chalcogenide Pyrochlore Lattice Materials
• Palmer-Chalker correlations in the XY pyrochlore antiferromagnet Er2Sn2O7
• Magnetic dilution and domain selection in the XY pyrochlore antiferromagnet Er${}_2$Ti${}_2$O${}_7$
• Low-field behavior of an XY pyrochlore antiferromagnet: emergent clock anisotropies
• Deviation from the dipole-ice model in the new spinel spin-ice candidate, MgEr${}_2$Se${}_4$
• Field induced phase diagram of the XY pyrochlore antiferromagnet Er${}_2$Ti${}_2$O${}_7$
• Experimental evidence for field induced emergent clock anisotropies in the XY pyrochlore Er${}_2$Ti${}_2$O${}_7$
• Low-temperature magnetisation process in the cubic pyrochlore quantum antiferromagnet, Er2Ti2O7
• Exchange interactions in two-state systems: rare earth pyrochlores
• Traversing the pyrochlore stability diagram; microwave-assisted synthesis and discovery of mixed B-site Ln${}_2$InSbO${}_7$ family
• Absence of long-range order in an $XY$ pyrochlore antiferromagnet Er${}_2$AlSbO${}_7$