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Manoj K. Singh

Publications and source records attributed to Manoj K. Singh.

2 recordsLinked to original sources
arXiv2008

Almeida-Thouless Line in BiFeO3: Is Bismuth Ferrite a mean field spin glass?

Low-temperature magnetic properties of epitaxial BiFeO3 thin films grown on (111)-SrTiO3 substrates have been studied. ZFC and FC magnetization curves show a large discrepency beginning at a characteristic temperature Tf that is dependent on the magnetic-field strengh. Tf(H) varies according to the well known de Aleimda-Thouless line (varies in Hexp(2/3)) suggesting an acentric long rnage spin-glass behavior and mean field system.

cond-mat.mtrl-sci↗
arXiv2008

One-magnon (electromagnon) light scattering in BiFeO3 single crystals

We observed Raman scattering from magnon in frequency range from 10 to 65 cm-1 in BiFeO3 single crystals at cryogenic temperatures; the temperature dependence of the magnon frequency at 18.2 cm-1 approximates an S=5/2 Brillouin function up to the temperature (280 K) at which the magnon becomes overdamped. The diverging cross-section and the frequency-shift at 140K and 200 K implies a magnon-reorientation transition as in orthoferrites. Magnons in polar materials such as BiFeO3 are often termed electromagnons meaning that they possess an electric dipole moment due to magnetoelectric coupling.

cond-mat.mtrl-sci↗