Fig. 4

Wait time and isotope dependences of magnetothermal avalanches. This gives further evidence of the effect of nuclear spins on the monopole mobility. Avalanches of the magnetisation were recorded while the field was ramped at 20 mT s⁻¹ for a ¹⁶² Dy₂Ti₂O₇ (¹⁶²Dy) and b ¹⁶³ Dy₂Ti₂O₇ (¹⁶³Dy), both measured at T = 80 mK, and c Ho₂Ti₂O₇ (HTO, measured at T = 200 mK). Magnetothermal avalanches for ^natDy₂Ti₂O₇ (DTO) can be seen in Supplementary Fig. 4. The samples were first prepared using the AQP and then followed by various wait times (as outlined in (d) and discussed in methods) except for the curves marked CC, where the sample was first prepared using the conventional zero field cooled protocol (red squares). Also shown for each of the samples is the equilibrium M vs. μ₀H taken at 900 mK (solid black dots). All measurements shown in the figure were made with the field along the [111] axis; examples for other directions are given in the Supplementary Figs. 9–11. e Plot of difference in avalanche field ΔH_ava = H_ava(t_w) − H_ava (t_w = minimum) against log wait time for the data shown in the left as well as ^natDy₂Ti₂O₇ (DTO, see Supplementary Fig. 4)