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

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.