2019 : Anionogenic Magnetism Combined with Lattice Symmetry in Alkali-metal Superoxide RbO2

Fahmi Astuti S.Si, M.Si, Ph.D


X-ray powder diffraction (XRPD), magnetic susceptibility and muon-spin relaxation (μSR) measurements were carried out to investigate lattice symmetries and magnetic properties of one of alkali-metal superoxides, RbO2. Two structural transitions were observed around 170 and 100 K in conjunction with the appearance of anomalies in the magnetic susceptibility. A static antiferromagnetic long-range ordered state of unpaired spins on dumbbells with the full magnetic volume fraction was confirmed from μSR below about 15 K. In comparison with CsO2, it is suggested that small changes in the lattice symmetry driven by changes in the dumbbell orientation causes different magnetic properties in alkali-metal superoxides.