Extended Data Figure 2 : ILG-induced phase transformations.

From: Electric-field control of tri-state phase transformation with a selective dual-ion switch

Extended Data Figure 2

a–d, In situ XRD results obtained near the LSAT(002) peak during phase transformations from: a, SrCoO2.5 to phase A (HSrCoO2.5); b, phase A (HSrCoO2.5) to SrCoO2.5; c, SrCoO2.5 to SrCoO3−δ; and d, SrCoO3−δ to SrCoO2.5, with fixed gating voltages of +3.5 V, −2.3 V, −2.7 V and +1.8 V, respectively. The dashed horizontal lines indicate when the phase transformation occurred. e–h, Summarized gating durations for transformations from: e, SrCoO2.5 to phase A (HSrCoO2.5); f, phase A (HSrCoO2.5) to SrCoO2.5; g, SrCoO2.5 to SrCoO3−δ; and h, SrCoO3−δ to SrCoO2.5, with different gating voltages. The gating duration is defined as the time required for the phase transformation to complete. All gating durations of less than 2,000 minutes were obtained from the in situ XRD measurements shown in a–d; for extended gating durations (more than 2,000 minutes), the data were obtained from the ex situ gating experiments (e, g). The black squares in e and g indicate that the initial SrCoO2.5 phase remains unchanged even after a gating duration of 2,880 minutes. Red and blue points correspond to negative and positive gating voltages, respectively. The vertical dashed lines indicate the electrolysis voltage of water. i, X-ray photoelectron spectroscopy measurements of the as-grown SrCoO2.5 (green) and ILG-induced SrCoO3−δ (red) and HSrCoO2.5 (blue) phases, grown on LSAT(001) substrate. The peaks represent the electron-binding energy of the specific atomic orbitals in selected elements. LMM and KLL refer to states in Auger electron spectroscopy. j, k, Reversible electric-field-induced, well defined transformations between SrCoO2.5 and phase A (HSrCoO2.5) (j) and between SrCoO2.5 and SrCoO3−δ (k) at selected gating voltages. The films of material were 50 nm thick. The gating experiments were performed in air with the as-received ionic liquid DEME-TFSI.