Spin-phonon coupling and giant dielectric constant in Bi 0.5 La 0.5 Fe 0.4 Al 0.1 Mn 0.5 O 3

In the present article, we report the magnetic, dielectric, and structural properties of the perovskite Bi 0.5 La 0.5 Fe 0.4 Al 0.1 Mn 0.5 O 3 . The structural analysis shows that this system crystallizes in a disordered orthorhombic phase with the space group Pnma . We found two consecutive magnetic transitions at 42 K and 147 K which have been suggested to be associated with the spin-glass and long-range ordering transitions, respectively. Further, temperature-dependent Raman spectra shows that this system has a spin-phonon coupling. Moreover, the dielectric measurement suggests that this system has a large dielectric constant at ambient temperature. Additionally, the dielectric spectrum suggests an unusual frequency-dependent step-like trend and the presence of weak relaxor ferroelectricity in the system. Thus, the presence of such multiple interesting characteristics suggests that Bi 0.5 La 0.5 Fe 0.4 Al 0.1 Mn 0.5 O 3 can be used as spintronic devices and high dielectric applications.