Signature of spin-phonon coupling in Sr2CoO4 thin film: A Raman spectroscopic study

Abstract

We have investigated the phonon spectra of pulsed laser deposited Sr2CoO4 thin film and its evolution with temperature using Raman spectroscopy. The magnetic measurement reveals magnetic transition at temperature TC = 255 K. No structural phase transition is observed in the investigated temperature range (100-300 K). Close correlation between the frequency shift and the magnetization across TC establishes that the anomaly in the vicinity of TC is owing to spin-phonon coupling in the material. Using two different approaches, we have calculated spin-phonon coupling strength to be in the range of 2-3.5 cm−1.

Crystal growth, structure, and dielectric properties of layered cobaltates La2−xSrxCoO4 (x=0.4, 0.5, and 0.6) single crystal

“…2. The proposed assignment is based on previous reports [17]. Studies on several crystals that exhibit a similar structure indicate that the Raman-active modes are mainly dominated by the internal modes of the CoO 6 octahedra and La (Sr) atoms (2 A 1 g + 2E 1 g ).…”

Probing spin–phonon coupling in magnetoelectric CaCu3Ti4O12–NiFe2O4 composite nanostructures

“…It is worth mentioning here that NFO is a ferrimagnetic material, which posses magnetic ordering temperature around 823 K. Therefore, single‐phase NFO/LAO film displays usual temperature dependence governed by anharmonic model function in the temperature range of 300–80 K. Neither dielectric phase nor the magnetic phase is accompanied by the any structural phase transition in the 50–600 K temperature range; we still observe anomalies in the A 1g mode position and full width at half maximum (corresponding to NFO phase) around 100 K for the composite films. The observed anomaly in the A 1g mode for the composite films is correlated to the sudden change in magnetization of NFO around 100 K. It is well known that the spin–spin correlation could renormalize the phonon dynamics via spin–phonon interaction . Therefore, the anomalous behaviour of the A 1g mode positions and linewidth can be attributed to the spin–phonon coupling in the composite films.…”

Spin and phonon anomalies in epitaxial self-assembled CoFe2O4-BaTiO3 multiferroic nanostructures

“…Figure 4(b) shows the A 1g phonon frequency consists well with fitted line except for slight drops at 180 K and 260 K, and strong deviation at 340 K. The phonon anomalies, including the softening of A 1g , A 1 (1TO), and A 1 (2TO) mode frequencies at 340 K, are correlated with the increased in-plane magnetization at 340 K. The spin-spin correlation could renormalize the phonon dynamics via spinphonon interaction. [33][34][35][36] According to a general spin-phonon coupling, 33,34 which is expressed as…”