Mesoscopic, non-equilibrium fluctuations of inhomogeneous electronic states in manganites
Serin Physics Laboratory, Rutgers University -
Piscataway, NJ 08854, USA
2 Bell Laboratories, Lucent Technologies - Murray Hill, NJ 07974, USA
Accepted: 17 May 2001
By using the dark-field real-space imaging technique of transmission electron microscopy (TEM), we have observed slow 200 scale fluctuations of charge-ordered (CO) phase in mixed-valent manganites under a strong electron beam irradiation. In addition to these unusual fluctuations of the CO phase, we observed switching-type fluctuations of electrical resistivity in the same sample, which were found to be as large as several percents. Systematic analysis indicates that these two different types of fluctuations with a similar time scale of the order of seconds are interconnected through a metastable insulating charge-disordered state. Current dependence of the fluctuations suggests a non-equilibrium nature of this slow dynamics.
PACS: 75.30.Vn – Colossal magnetoresistance / 68.37.Lp – Transmission electron microscopy (TEM) (including STEM, HRTEM, etc.) / 74.40.+k – Fluctuations (noise, chaos, nonequilibrium superconductivity, localization, etc.)
© EDP Sciences, 2001