CONTROL OF THE ELECTRORESISTANCE EFFECT OBTAINED IN Pr0.5Ca0.5MnO3 MAGNETIC OXIDE THIN FILM BY ELECTROSTATIC FIELD IN A FERROELECTRIC/MANGANITE OPTIMIZED DEVICE

摘要

The aim of this study is to probe the effect of an electric field on charge ordered (CO) magnetic compounds. Thus, we have fabricated a three-terminal device analogous to a field-effect transistor (FET), using the Pr_(0.5)Ca_(0.5)MnO_3 (PCMO) charge-ordered manganite as the channel material and ferroelectric PbZr_xTi_(1-x)O_3 (PZT) as the gate insulator. The optimized technological process is based on five UV lithography levels. In such ferroelectric FET under gate polarization, and with PCMO channel in which coexist magnetic metallic regions and an insulating matrix, an ER effect of 39%, that is associated to a modulation of the manganite channel conductivity, under the electrostatic field, was measured under V_G = ± 6 V, for temperatures lower than the charge ordered temperature (T<220K). The accumulation (or the depletion) of the carriers controlled by the electrostatic field and the percolation of the grown metallic phases in the insulator matrix will be discussed for interpreting the changes of the manganite resistance.