Magnetic and transport properties of Mn oxides films

A huge (colossal) magnetoresistance (CMR) recently observed in perovskite Mn oxides has attracted much interest in both basic science research and technological applications. Many studies have been undertaken from the standpoints of clarifying the origin of the CMR, the search for new phenomena, materials design of the strongly correlated electrons systems, and so on. In this article we present a brief review on one aspect of the CMR effect, that is controllability of the MR of Mn oxides. The discussion concentrates on two areas - control of the geometry of the systems and control of the internal degree of freedom which is related to the electronic states of the manganites, i.e. the orbital states of the Mn ions.