Abstract
At the critical point of a first-order electronic phase transition, fluctuations between the competing phases are often a dominant phenomenon. The direct observation of these fluctuations in electronic phases is vital to revealing the microscopic details of the phase transition. This is especially true in strongly correlated transition metal oxides, in which a diversity of electronic phases coexist and are closely connected to several remarkable properties such as high-Tc superconductivity and colossal magnetoresistance. Here we report a novel and generic approach that directly records the fluctuations of the electronic phases at the critical point of the metal-insulator transition, using a manganite system as example. In our approach, we reduce a single crystal thin film of La5/8-xPrxCa3/8MnO3 to the scale of its inherent electronic charge ordered insulating (COI) and ferromagnetic metal (FMM) phase domains and conduct high resolution resistance vs. time measurements within a critical regime of temperature and magnetic field at the metal insulator transition (MIT). Within this window, we are able to observe individual domains as they fluctuate between COI and FMM.
