Evidences of a consolute critical point in the Phase Separation regime of La(5/8-y)Pr(y)Ca(3/8)MnO(3) (y = 0.4) single crystals

TL;DR

This study investigates the electric field-induced phase transition in La(5/8-y)Pr(y)Ca(3/8)MnO(3) single crystals, revealing a critical point where conducting and insulating phases separate, indicating a phase transition akin to a consolute point.

Contribution

It provides experimental evidence of a consolute critical point in the phase separation regime of manganite single crystals, linking electric field effects to phase criticality.

Findings

Electric field induces irreversible transition from high to low resistivity.

Critical voltage V_c depends on temperature, indicating a critical point.

No change in magnetization suggests filamentary conduction paths.

Abstract

We report on DC and pulsed electric field sensitivity of the resistance of mixed valent Mn oxide based La(5/8-y)Pr(y)Ca(3/8)MnO(3) (y = 0.4) single crystals as a function of temperature. The low temperature regime of the resistivity is highly current and voltage dependent. An irreversible transition from high (HR) to a low resistivity (LR) is obtained upon the increase of the electric field up to a temperature dependent critical value (V_c). The current-voltage characteristics in the LR regime as well as the lack of a variation in the magnetization response when V_c is reached indicate the formation of a non-single connected filamentary conducting path. The temperature dependence of V_c indicates the existence of a consolute point where the conducting and insulating phases produce a critical behavior as a consequence of their separation.