Signatures of Weak Spin-Phonon Coupling in 12R-BaTi0.4Mn0.6O3: A Raman Study.

Antiferromagnetic materials with strong spin-phonon coupling have the potential for spintronic applications. Here, we report the structural, magnetic, and vibrational properties of 12R-BaTi0.4Mn0.6O3. Temperature-dependent magnetization data show the presence of weak antiferromagnetic interactions. Correlation between magnetic and vibrational properties are probed by using temperature-dependent Raman spectroscopic measurements. Two of the Raman active phonons show deviation from anharmonic behaviour at low temperatures which can be attributed to spin-phonon coupling. The strength of coupling is estimated using mean-field approximation and is found to be 1.1 and 1.2 cm-1 for phonons at 530 and 717 cm-1, respectively.