Probing Magnetoelastic Coupling and Structural Changes in Magnetoelectric Gallium Ferrite

Abstract

Temperature dependent X-ray diffraction and Raman spectroscopic studies were carried out on the flux grown single crystals of gallium ferrite with Ga:Fe ratio of 0.9:1.1. Site occupancy calculations from the Rietveld refinement of the X-ray data led to the estimated magnetic moment of ~0.60 \muB /f.u. which was in good agreement with the experimental data. Combination of these two measurements indicates that there is no structural phase transition in the material between 18 K to 700 K. A detailed line shape analysis of the Raman mode at ~375 cm^-1 revealed a discontinuity in the peak position data indicating the presence of spin-phonon coupling in gallium ferrite. A correlation of the peak frequency with the magnetization data led to two distinct regions across a temperature ~180 K with appreciable change in the spin-phonon coupling strength from ~ 0.9 cm^-1 (T < 180 K) to 0.12 cm-1 (180 K < T < Tc). This abrupt change in the coupling strength at ~180 K strongly suggests an altered spin dynamics across this temperature.

16 pages, 4 figures

References in corpus (4)

• Magnetoelectric response of multiferroic BiFeO3 and related materials
• Electronic Structures, Born Effective Charges and Spontaneous Polarization in Magnetoelectric Gallium Ferrite
• Magneto-electric excitations in multiferroic TbMnO3 by Raman scattering
• Strong magnetoelastic effect on the magnetoelectric phenomena of TbMn${}_2$O${}_5$

Cited by in corpus (7)

• Room Temperature Nanoscale Ferroelectricity in Magnetoelectric GaFeO3 Epitaxial Thin Films
• Composition Dependence of Structural Parameters and Properties of Gallium Ferrite
• Spin Glass-like Phase below ~ 210 K in Magnetoelectric Gallium Ferrite
• Coupled Phonons, Magnetic Excitations and Ferroelectricity in AlFeO3: Raman and First-principles Studies
• Phase Stability of Multiferroic GaFeO3 up to 1368 K from In situ Neutron Diffraction
• First Principle Study of Magnetism and Magneto-structural Coupling in Gallium Ferrite
• Spin-Phonon Coupling, High Pressure Phase Transitions and Thermal Expansion of Multiferroic GaFeO3: A Combined First Principles and Inelastic Neutron Scattering Study