Abstract
In this thesis, we investigated magnons in the fully concentrated rare-earth crystals gadolinium vanadate and erbium lithium fluoride.
Experiments exploring low temperature magnetic properties of rare-earth crystals have often been carried out at a single frequency. We designed and built a coplanar waveguide and a coaxial resonator, which could probe the magnons over multiple frequencies, allowing us to gain more information from a single setup.
Gadolinium vanadate and erbium lithium fluoride both order antiferromagnetically at sufficiently low temperatures. Driving the crystals with a resonant AC magnetic field excites magnon modes, which are quantised spin waves. This thesis adds to the knowledge of magnons in rare-earth crystals, and gives us some ideas for future investigations.