MSc thesis defense by Timmy Anker Sode

Titel: Exotic spin textures and magnetic correlations in Ytterbium Ortho-Niobate 

Abstract: In geometrically frustrated magnetic systems, competing exchange interactions can inhibit conventional magnetic ordering, even at very low temperatures. Rare-earth compounds, where magnetic ions are embedded in complex crystal lattices are especially intriguing because of the interplay between lattice geometry, electronic configuration, and magnetic interactions, giving rise to exotic spin states, such as spin liquids or spin ice that are disordered down to T = 0 K

This defense will elaborate on the exploration of exotic spin textures and magnetic correlations in the chemically disordered and magnetically frustrated system YbNb1−xSbxO4.

XRD and neutron diffraction techniques were employed to characterize the atomic structure at room temperature and at 2 K.

High-resolution neutron scattering experiments were conducted at the high-intensity spin-echo spectrometer, WASP, and the thermal neutron time-of-flight spectrometer, PANTHER. Polarized neutrons were used at WASP, allowing the magnetic scattering contribution to be separated from the nuclear scattering contribution. The magnetic contribution indicated magnetic correlations of Yb3+ at 2 K, indicating a single ion effect.

Supervisor: Kim Lefmann

Censor:  Niels Bech Christensen (DTU)