Spin induced exchange bias and lattice modulation in Nd1-xEuxCrO3

We report the evolution of coupled phonons and exchange bias (EB) in perovskite-type Nd1-xEuxCrO3 (x = 0.0, 0.05, and 0.10) samples by means of temperature-dependent Raman spectroscopy and dc magnetization measurements. We observed a non-monotonic behavior of the EB field around the temperature T*, which lies between the antiferromagnetic ordering temperature (T-N) and spin-reorientation transition temperature (T-SR). The temperature dependence of phonon modes related to antistretching and bending of CrO6 octahedra and Nd3+/Eu3+ ion vibration below T-N confirms the strong spin-phonon coupling. The T* found from the non-monotonicity of the EB is imprinted with the additional anomaly observed in the low-temperature spin-phonon behavior. The phonon modes and phonon anomaly are also verified using the density functional theory-based calculations.

Automated summary

The evolution of coupled phonons and exchange bias in perovskite-type Nd1-xEuxCrO3 samples was studied through temperature-dependent Raman spectroscopy and dc magnetization measurements. Non-monotonic behavior of the EB field around T* was observed, with T* lying between T-N and T-SR, confirming strong spin-phonon coupling through temperature dependence of phonon modes. The additional anomaly observed in low-temperature spin-phonon behavior was imprinted in T* from the non-monotonicity of the EB.