Figure 5
From: Inverse Tunnel Magnetocapacitance in Fe/Al-oxide/Fe3O4
Band diagram of Fe and Fe3O4. (a) P and (b) AP configurations. The DOS of Fe is calculated by tight-binding linear muffin-tin orbital in the atomic sphere approximation (TB-LMTO-ASA) method and that of Fe3O4 is obtained from ref. 28. The Fermi level E F is at 0 eV. The DOS in the left and right sides represents the energy band of spin-up (red) and spin-down (blue) electrons, respectively. The E F of Fe (gray panel) goes up for V > 0 V and that of Fe3O4 (orange panel) goes up for V < 0 V, relatively to each other. The band calculation suggests that the conductance G AP is larger than G P, in other words, the relaxation time τ AP is shorter than τ P, indicating the appearance of inverse TMC. This inverse TMC is strongly dependent on the bias voltage V and its behavior is changed by the polarity of V. The mechanism is discussed in the main text.
