Probing Magnetoelastic Coupling and Structural Changes in Magnetoelectric Gallium Ferrite
| Autor: | Mukherjee, Somdutta, Gupta, Rajeev, Garg, Ashish |
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| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | J. Phys.: Condens. Matter 23 (2011) 445403 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0953-8984/23/44/445403 |
| Popis: | 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. Comment: 16 pages, 4 figures |
| Databáze: | arXiv |
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