Unveiling instability in Cr-doped Nd0.5Ca0.5MnO3

The magnetic phase transition and insulating-metal phase transition in the charge ordering (CO) Nd0.51Ca0.49Mn0.98Cr0.02O3 system have been studied. From the magnetization and resistivity measurements, a considerable instability is observed in the temperature region 40K⩽T⩽135K upon thermal cycle. In the thermal hysteresis region, both antiferromagnetic (AFM) and paramagnetic (PM) phases transform into ferromagnetic (FM) phase as the temperature decreases, thus the strong ferromagnetism emerges in the system. The origin of the instability should be attributed to the strain relaxation in the interfacial region. Interestingly, due to the growing FM interaction, the AFM coupling becomes weakened rather than strengthened at low temperatures.