У оквиру семинара Центра за физику чврстог стања и нове материјале, у петак, 6. марта 2026. године у 12 часова у читаоници библиотеке „Др Драган Поповић“, др Бојан Стојадиновић (Центар за физику чврстог стања и нове материјале, Институт за физику у Београду) одржаће предавање:
Raman Spectroscopy as a tool for studying spin–phonon coupling in multiferroic nanomaterials
САЖЕТАК:
Spin–phonon interaction is a key mechanism influencing the magnetic, ferroelectric, and magnetoelectric properties of nanostructured multiferroic systems. Multiferroic materials, such as BiFeO3, exhibit multiple ordered states (ferroelectric and antiferromagnetic), while related magnetic oxides, such as rare-earth iron garnets, share a similar type of interaction between the lattice and magnetic subsystems, arising from strongly correlated d- and f-electrons of magnetic ions. In nanostructured magnetic materials, this coupling manifests as anomalous temperature-dependent shifts of optical phonon frequencies, particularly in the region of the magnetic phase transition, where significant changes in spin–spin correlations occur. Raman spectroscopy has proven to be an extremely sensitive method for detecting these effects, as it allows monitoring of deviations of phonon modes from expected anharmonic behavior. By analyzing these deviations and applying mean-field theory approaches to describe spin–spin correlations, it is possible to quantify the strength of spin–phonon coupling. Within these studies, both multiferroic and magnetic systems have been considered, and interaction parameters for different phonon modes have been determined.