Abstract
We report electron spin resonance (ESR), Raman scattering, and interband absorption measurements of the multiferroic FeTe2O5Br with two successive magnetic transitions at TN1 = 11.0 K and TN2 = 10.5 K. ESR measurements show all characteristics of a low-dimensional frustrated magnet: (i) the appearance of an antiferromagnetic resonance (AFMR) mode at 40 K, a much higher temperature than TN1, and (ii) a weaker temperature dependence of the AFMR linewidth than in classical magnets, ΔHpp(T) ∝ Tn with n = 2.2–2.3. Raman spectra at ambient pressure show a large variation of phonon intensities with temperature while there are no appreciable changes in phonon numbers and frequencies. This demonstrates the significant role of the polarizable Te4+ lone pairs in inducing multiferroicity. Under pressure at P = 2.12–3.04 GPa Raman spectra undergo drastic changes and absorption spectra exhibit an abrupt drop of a band gap. This evidences a pressure-induced structural transition related to changes of the electronic states at high pressures.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
