Figure 3. Temperature and momentum dependence of excitation E_A.

(a) RIXS spectra at constant q=(2.5,8.8,8.8) and fixed incident energy E_i=10.877 KeV at several temperatures through the magnetic MIT in Cd₂Os₂O₇ reveals E_A as a temperature dependent excitation. (b) The low-energy excitation (E_A=160 meV), along with the elastic line, was fit to a Gaussian on a background from the higher energy scattering at 60 K (red diamonds) and 250 K (grey squares). (c) The intensity at E_A appears and increases below the magnetic MIT temperature of 225 K, the line is a least squares fit to a power law. (d) RIXS measurements in the magnetic insulating regime at T=60 K performed along high-symmetry directions in the magnetic Brillouin zone. The elastic scattering was suppressed by measuring within 4° of 2θ=90°, the remaining elastic signal has been subtracted from the data. (Inset) The Brillouin zone in the (HKK) plane is shown (grey) and the directions measured (red). (e) The inelastic energy and (f) intensity dependence of E_A reveal dispersionless behaviour for E_A. Error bars throughout the figure represent the s.d. in the data fitting procedure.