Giant Electric Field Modulation of Double Exchange Ferromagnetism at Room Temperature in the Perovskite Manganite/Titanate p−n Junction

We report on the electrical modulation of double exchange ferromagnetism at room temperature in hole-doped manganites of a metal oxide p-n junction. In this (La0.9Ba0.1)MnO₃/Nb doped SrTiO₃ p-n junction, the temperature dependence of the junction resistance shows a metal-insulator transition whose temperature, corresponding to that of ferromagnetic transition, is hugely modulated from 290 to 340 K by a bias voltage increasing from $+1.0$ to +1.8V. The magnetoresistance can also be modulated electrically.