Fig. 2 | Nature Communications

Fig. 2

From: Fragmentation in spin ice from magnetic charge injection

Fig. 2

Magnetic ordering and diffuse scattering in Ho2Ir2O7. a Neutron diffractograms recorded at 200 K (red dots) and 1.5 K (green dots) showing the rise of magnetic Bragg peaks. The 1.5 K Rietveld refinement (black line) using a k = 0 propagation vector yields an AIAO magnetic order for the holmium sublattice. The difference between the 1.5 and 200 K data (blue line, shifted for clarity) enhances the magnetic Bragg peaks. b Temperature evolution of the refined Ho3+ magnetic moment, in a semi-logarithmic scale, measured with two diffractometers (D1B and G4.1). The red dashed curve is the calculated ordered magnetic moment induced by the temperature dependent molecular field created by the Ir magnetic ordering. Below 20 K, the calculated and experimental curves depart from each other due to the presence of Ho-Ho magnetic interactions. The red full curve is obtained from Monte Carlo calculations (Eq. (1)) with \({{\cal J}_{{\rm{eff}}}}\) = 1.4 K and h loc/\({{\cal J}_{{\rm{eff}}}}\) = 4.5, the colored area representing the calculated values compatible with the experimental error bars (within symbol size). These calculations allow to account for the saturation of the ordered moment below 2 K due to fragmentation. The departure above 40 K between the calculated and experimental curves is attributed to the decrease of the Ir molecular field. c Evidence for diffuse scattering at 1.5 K, from the difference between the 1.5 and 200 K diffractograms (the negative intensity is due to an imperfect subtraction of a strong nuclear peak caused by the lattice parameter variation). d Powder average magnetic scattering function S(Q) from Monte Carlo calculations at T/\({{\cal J}_{{\rm{eff}}}}\) = 0.05 with h loc/\({{\cal J}_{{\rm{eff}}}}\) = 4.5

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