Abstract
Electrical transport properties of a sample composed of small iron particles of several tens nm was studied in the temperature range 1.8-300 K. TEM study indicates that each small particle is covered with a very homogeneous epitaxial gamma -Fe sub 2 O sub 3 shell that prevents further oxidization of the metal particles. The temperature dependence of resistivity R(T) and the field- dependent current density in the high-field range can be well described by the theory of fluctuation-induced tunneling conduction.