Abstract: Hybridization mechanisms of atomic vibrational and spin excitations are of critical importance in understanding the control of both magnetic relaxation in magnetic materials and energy transportation and functionalities in energy materials. Understanding and controlling these mechanisms provides critical knowledge towards the emergence of novel materials for energy transport and conversion as well as quantum information science.

We target phenomena where lattice and spin dynamics are modified by a strong deviation from harmonic behavior, strong coupling of spins to disorder and to the lattice, and strong quantum fluctuations. I will discuss these effects of disorder in situations such as doping-induced spin-reorientation in antiferromagnetic MnTe, magnetic dilution in antiferromagnetic TbSb, electric-field poling in the relaxor ferroelectric PMN-xPT, and strong vibrational mode coupling in rutile TiO₂. I study these effects using a combination of spectroscopic and diffraction techniques such as inelastic neutron scattering, neutron diffraction Mössbauer, and nuclear inelastic scattering. Understanding these phenomena will promote the development of novel materials with tailored thermal and magnetic transport and quantum ferroic properties.