Scaling description of non-Ohmic transport in manganites

Abstract: The current–voltage characteristics of several manganite systems like , and show non-Ohmic behaviour at different temperatures. The onset voltage at which conductance starts deviating from its zero-bias value scales as with x T being the onset exponent. A detailed scaling analysis with these manganite systems reveal that the onset exponents x T are different in the paramagnetic insulating and ferromagnetic metallic phases. Besides, the magnitudes of x T are different in different manganite systems. Non-Ohmic conduction and the onset exponent are described with the help of inelastic multi-step tunneling model and scaling concepts. [Copyright &y& Elsevier]