Open Access

Markus Prinz-Zwick

• The two multiferroic skyrmion host materials, namely the lacunar spinels GaV4S8 and GaV4Se8, were investigated via an extensive NMR study. The polar properties were probed via the quadrupolar interaction of the 71Ga nuclei, while magnetic properties are studied via the hyperfine fields at the magnetic 51V nuclei. The multiferroic order parameters (polarization and magnetization) are correlated with the local order parameters (quadrupolar splitting and hyperfine shift, respectively), which are obtained in the NMR study . The local order parameters differ between domains for arbitrary magnetic field directions due to anisotropy effects, and multiferroic domain populations are therefore obtained from NMR spectra. Further control of the domain population via electric and magnetic poling fields is accompanied by the NMR study, tracking the evolution of the domain population. Furthermore, the spin distribution over the V4S4 cluster is reconstructed via measurements of the anisotropy of theThe two multiferroic skyrmion host materials, namely the lacunar spinels GaV4S8 and GaV4Se8, were investigated via an extensive NMR study. The polar properties were probed via the quadrupolar interaction of the 71Ga nuclei, while magnetic properties are studied via the hyperfine fields at the magnetic 51V nuclei. The multiferroic order parameters (polarization and magnetization) are correlated with the local order parameters (quadrupolar splitting and hyperfine shift, respectively), which are obtained in the NMR study . The local order parameters differ between domains for arbitrary magnetic field directions due to anisotropy effects, and multiferroic domain populations are therefore obtained from NMR spectra. Further control of the domain population via electric and magnetic poling fields is accompanied by the NMR study, tracking the evolution of the domain population. Furthermore, the spin distribution over the V4S4 cluster is reconstructed via measurements of the anisotropy of the hyperfine coupling for different field rotation planes. Atomic d orbitals are placed on each atomic site, and the orbital parameters are fitted to the NMR data by calculating the dipole contribution of the hyperfine field and comparing it with the experiments.…