Origin of colossal magnetoresistance in LaMnO3 manganite
Maria Baldini1, Takaki Muramatsu2, Mohammad Sherafati3
1High Pressure Synergetic Consortium, Geophysical Laboratory,Carnegie Institution of Washington, Argonne, IL 60439; mbaldini@carnegiescience.edu mao@gl.ciw.edu.
Abstract:
Phase separation is a crucial ingredient of the physics of manganites; however, the role of mixed phases in the development of the colossal magnetoresistance (CMR) phenomenon still needs to be clarified. We report the realization of CMR in a single-valent LaMnO3 manganite. We found that the insulator-to-metal transition at 32 GPa is well described using the percolation theory. Pressure induces phase separation, and the CMR takes place at the percolation threshold. A large memory effect is observed together with the CMR, suggesting the presence of magnetic clusters. The phase separation scenario is well reproduced, solving a model Hamiltonian. Our results demonstrate in a clean way that phase separation is at the origin of CMR in LaMnO3.
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