Školitel: Doc. Mgr. Martin Setvín, Ph.D.
Stav práce: volná
Anotace:
Polarons are quasiparticles that originate from coupling of excess electrons or holes with lattice vibrations [1]. They play a central role in many materials properties, such as electric transport, optical properties, surface reactivity, superconductivity or magnetoresistance. Certain types of polarons (small polarons) can localize at a single lattice site, become immobile and exhibit hopping motion. The task of this Thesis is using the noncontact Atomic Force Microscopy to observe these localized polarons and investigate their hopping kinetics induced by thermal fluctuations, light or tip’s electric field. The system of choice will be mainly perovskites that are close to the ferroelectric state, namely titanates and tantalates for (KTaO3, KNbO3, SrTiO3 or BaTiO3). A part of the challenge lies in distinguishing the polarons from ferroelectric polarization, which is easily induced by the tip.
The candidate will be encouraged to spend at least 6 months abroad with one of our collaborators in Austria, Germany or Japan.