Magnon spectra and strong spin-lattice coupling in magnetically frustrated MnB2O4 (B = Mn,V): Inelastic light scattering studies
Abstract
The ferrimagnetic spinels MnB2O4 (B = Mn,V) exhibit a similar series of closely spaced magnetic and structural phase transitions at low temperatures, reflecting both magnetic frustration and a strong coupling between the spin and lattice degrees of freedom. Careful studies of excitations in MnB2O4 (B = Mn,V), and the evolution of these excitations with temperature, are important for obtaining a microscopic description of the role that magnetic excitations and spin-lattice coupling play in the low temperature phase transitions of these materials. We report an inelastic light (Raman) scattering study of the temperature and magnetic field dependences of one- and two-magnon excitations in MnV2O4 and Mn3O4. We observe a pair of q=0 one-magnon modes at 74 cm-1 and 81 cm-1 in MnV2O4, which is in contrast with the single 80 cm-1 q=0 magnon that has been reported for MnV2O4 based on previous neutron scattering measurements and spin wave calculations. Additionally, we find that the two-magnon energy of MnV2O4 decreases ("softens") with decreasing temperature below TN, which we attribute to strong coupling between magnetic and vibrational excitations near the zone boundary.
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.