Dirty Peierls transition to stripe phase in manganites

S. Cox; J. C. Lashley; E. Rosten; J. Singleton; A. J. Williams; P. B. Littlewood

paper

Dirty Peierls transition to stripe phase in manganites

arXiv:cond-mat/0610276

Abstract

The nature of the phase transitions in La $_{1 - x}$ Ca $_{x}$ MnO $_{3}$ and Pr $_{0.48}$ Ca $_{0.52}$ MnO $_{3}$ has been probed using heat capacity and magnetisation measurements. The phase transition associated with the onset of the stripe phase has been identified as second order. The model of a Peierls transition in a disordered system (a `dirty' Peierls transition) is shown to provide an extremely good fit to this transition. In addition, an unexpected magnetic phase has been revealed in low temperature Pr $_{0.48}$ Ca $_{0.52}$ MnO $_{3}$ , associated with an excess heat capacity over a wide temperature range compared to La $_{1 - x}$ Ca $_{x}$ MnO $_{3}$ .