| Several materials present the phenomenon of phase separation, where the bulk properties in some ranges of composition and temperature are dominated by the competition of two very different phases, typically one metallic and another insulating. In a phase separated state, coexisting clusters of the two phases are formed. What occurs when the dimensions of the sample become comparable to the dimension of these clusters? In a collaboration between experimentalists and theorists of ORNL and UT, this issue was investigated. It was observed that in effective one-dimensional systems, when the shortest length of the sample is smaller than the phase separated cluster size, an exotic phenomenon occurs: two metal insulator transitions in the same sample were observed by varying the temperature. This indicates that the behavior of a material can be altered by changing its dimensionality in the regime of phase separation. Phys. Rev. Lett. 100 247204 (2008) |