Fig. 2

Momentum dependence of the spin excitations in Li_0.8Fe_0.2ODFeSe at T = 5 K. a–j Constant-energy images acquired at 5 K and at indicated energies. |Q|-dependent background was subtracted in a–e (Supplementary Note 4). For energies ≥85 meV, raw data are presented, f–j. The measurements in a and b–j were conducted at the incident neutron energies of 49.6 and 191.6 meV, respectively. Symmetry equivalent data were collected and averaged to enhance statistical accuracy. The color bar indicates scattering intensity in unit of mbr sr⁻¹ meV⁻¹ f. u.⁻¹