Reversible shift of the transition temperature of manganites in planar field-effect devices patterned by atomic force microscope

Publisher Website
Google Scholar
Abstract
A planar side-gate device for field effect with a La 0.67 Ba 0.33 MnO 3 channel on a SrTiO 3 substrate is fabricated by means of the voltage-biased tip of an atomic force microscope. The peculiar geometry and the high dielectricpermittivity of the substrate enhance the channel resistance modulation up to 20% at low temperature by a gate voltage of ±40 V. Moreover, a reversible shift by 1.3 K of the metal–insulator transition temperature (T MI ) by field effect is observed. The signs of the changes of resistance and T MI both depend on the sign of the gate voltage, as expected for pure field effect; in particular, the T MI is raised (lowered) by accumulating (depleting) holes in the channel.