Voltage induced local hysteretic phase switching in silicon

Abstract

We report the observation of dc-bias induced 180° phase switching in silicon wafers by local-probe microscopy and spectroscopy. The switching is hysteretic and shows remarkable similarities with polarization switching in ferroelectrics as seen in piezoresponse force microscopy (PFM). This is always accompanied by a hysteretic amplitude vs. voltage curve which resembles the “butterfly loops” for piezoelectric materials. From a detailed analysis of the data obtained under different environmental and experimental conditions, we show that the hysteresis effects in phase and amplitude do not originate from ferro-electricity or piezoelectricity. This further indicates that mere observation of hysteresis effects in PFM does not confirm the existence of ferroelectric and/or piezoelectric ordering in materials. We also show that when samples are mounted on silicon for PFM measurements, the switching properties of silicon may appear on the sample even if the sample thickness is large.

Direct evidence of strong local ferroelectric ordering in a thermoelectric semiconductor

“…The possibility of electrochemical reactions under the tip is ruled out by topographic imaging after the spectroscopic measurements, where we do not observe any topographic modification that is usually expected to result from tip-induced electrochemical processes [25]. However, ruling out the above-mentioned possibilities with absolute certainty may not be possible by spectroscopic measurements alone.…”

“…The representative butterfly loops measured at three different points on AgSbSe 2 are shown in Observation of hysteretic phase switching and "butterfly loops" indicate that AgSbSe 2 has ferroelectric and piezoelectric properties. However, it should also be noted that such hysteresis in phase and amplitude may also arise from electrostatic and electrochemical effects [25]. In order to minimize the role of the electrostatic effects, all the measurements were performed following SS-PFM (switching spectroscopy piezoresponse force microscopy) pioneered by Jesse et.al.…”

Characterization of LiMn2O4 cathodes by electrochemical strain microscopy

“…On the other hand, high voltage may result in the appearance of additional contributions. 5,9,18 That is why we used ESM mapping with ramped AC voltage applied at each point to reveal how high AC voltage can influence the resulting signal. Figure 4 shows the spatial maps and extracted ESM amplitudes for both samples.…”

Li transport in fresh and aged LiMn2O4 cathodes via electrochemical strain microscopy

“…23 Though the first order Jahn-Teller distortion does not break the inversion symmetry, the structural transformation/electrochemical reaction can manifest itself as butterfly-like amplitude response and phase switching that were observed under very high applied voltage. 28 Additionally, static long-range ordering of JahnTeller polarons and local charge ordering under external electric field in manganites can induce lattice distortion that can break the structural inversion symmetry and provoke local ferroelectric-like response. 20,[29][30][31] Though it was not reported in LiMn 2 O 4 so far, we cannot exclude a possibility of emergence of ferroelectric-like state (localized in time and space), which is difficult to assess numerically.…”