Critical behavior of Griffiths ferromagnets

From a heuristic calculation of the leading order essential singularity in the distribution of Yang-Lee zeroes, we obtain new scaling relations near the ferromagnetic-Griffiths transition, including the prediction of a discontinuity on the analogue of the critical isotherm. We show that experimental data for the magnetization and heat capacity of La0.7Ca0.3MnO3 are consistent with these predictions, thus supporting its identification as a Griffiths ferromagnet.