Multiferroic bismuth ferrite: Perturbed angular correlation studies on its ferroic α−β phase transition

A perturbed-angular-correlation study of the ferroic α to β phase transition in multiferroic bismuth ferrite (BiFeO₃).

A radioactive probe is implanted or substituted into the crystal. The angular correlation of its decay gammas is perturbed by the local electric field gradient, which jumps when the crystal changes phase.

BiFeO₃ is a room-temperature multiferroic. Seeing the α-β transition at the probe site is a local, isotope-scale check of a transition that bulk magnetometry and diffraction also claim.