Pressure sensitivity of the ferromagnetic transition in perovskite manganites revisited

Abstract

It was already shown that a qualitative understanding of the pressure effects on the ferromagnetic transition temperature (Tc) of the perovskite manganites (AMnO3) results from the variation of the geometric factors that control the bandwidth, the Mn-O-Mn bond angle and the Mn-O bond length and also from the reduction of the effective mass related to the polaronic nature of the carriers. But, up to now, a quantitative agreement was not really obtained, particularly for the hole-doped manganites. Here, we present results on the pressure effects in the Tc of La 0.8(Ca,Sr)0.2MnO3 ceramic samples. Our results are described within a phenomenological approach based on the well known dependence of Tc on the mean A ionic radius, that gives a good quantitative agreement of the pressure sensitivity of Tc for several hole-doped manganites. © 2006 American Institute of Physics.