Jahn–Teller distortion and magnetocaloric synergy in Dy0.5R0.5Fe0.75Mn0.25O3

Abstract Magnetostructural studies of Dy0.5R0.5Fe0.75Mn0.25O3 (R = Dy, Gd and Ho) are carried out to study the effect of interaction between the A-site and B-site cations and how they affect the Jahn–Teller distortion, magnetic anisotropy, spin–phonon coupling and magnetocaloric properties. The Dy0.5R0.5Fe0.75Mn0.25O3 (R = Dy, Gd and Ho) compounds are found to be crystallized in the orthorhombic (Pnma) structure. Around the spin reorientation temperature, a strong anomaly is observed in the intensity, line width and phonon frequency of Raman vibrational modes which indicate the presence of strong spin–phonon coupling. While all the systems exhibit spin–phonon coupling, Gd-substituted DyFe0.75Mn0.25O3 is found to have the strongest spin–phonon coupling and this is distinctly related to the extent of octahedral distortion. A large magnetic entropy change is achieved in Dy0.5Gd0.5Fe0.75Mn0.25O3 (25.08 J (kg K)−1) which is attributed to the strong spin- phonon coupling present in the system.