Field-induced avalanche to the ferromagnetic state in the phase-separated ground state of manganites

Perovskite manganite compounds such as Pr1˛xsCa1˛ySrydxMnO3 can be tuned to exhibit a metastable ground state where two magnetic/crystallographic phases coexist in zero magnetic field. Field-dependent neutron diffraction measurements on both poly- and single-crystal samples with a range of Pr, Ca, and Sr dopings (0.3 x 0.35 and y 0.30) reveal that the charge ordered, antiferromagnetic phase of the ground state suddenly and irreversibly jumps to the ferromagnetic state. The transition occurs spontaneously at some time after the field is set above a threshold field, indicating that once the transition is initiated an avalanche occurs that drives it to completion.