Affordable Access

Access to the full text

Coupled Phonons, Magnetic Excitations and Ferroelectricity in AlFeO3: Raman and First-principles Studies

  • Kumar, Pradeep
  • Bera, A.
  • Muthu, D. V. S.
  • Shirodkar, S. N.
  • Saha, R.
  • Shireen, A.
  • Sundaresan, A.
  • Waghmare, U. V.
  • Sood, A. K.
  • Rao, C. N. R.
Published Article
Publication Date
Apr 28, 2012
Submission Date
Apr 28, 2012
DOI: 10.1103/PhysRevB.85.134449
External links


We determine the nature of coupled phonons and magnetic excitations in AlFeO3 using inelastic light scattering from 5 K to 315 K covering a spectral range from 100-2200 cm-1 and complementary first-principles density functional theory-based calculations. A strong spin-phonon coupling and magnetic ordering induced phonon renormalization are evident in (a) anomalous temperature dependence of many modes with frequencies below 850 cm-1, particularly near the magnetic transition temperature Tc ~ 250 K, (b) distinct changes in band positions of high frequency Raman bands between 1100-1800 cm-1, in particular a broad mode near 1250 cm-1 appears only below Tc attributed to the two-magnon Raman scattering. We also observe weak anomalies in the mode frequencies at ~ 100 K, due to a magnetically driven ferroelectric phase transition. Understanding of these experimental observations has been possible on the basis of first-principles calculations of phonons spectrum and their coupling with spins.

Report this publication


Seen <100 times