Song, Seul Ji Kim, Yu Jin Park, Min Hyuk Lee, Young Hwan Kim, Han Joon Moon, Taehwan Do Kim, Keum Choi, Jung-Hae Chen, Zhihui Jiang, Anquan Hwang, Cheol Seong 2024-01-20T05:02:13Z 2024-01-20T05:02:13Z 2021-09-05 2016-02 2045-2322 https://pubs.kist.re.kr/handle/201004/124440 Recent claim on the direct observation of a negative capacitance (NC) effect from a single layer epitaxial Pb(Zr-0.2, Ti-0.8)O-3 (PZT) thin film was carefully reexamined, and alternative interpretations that can explain the experimental results without invoking the NC effect are provided. Any actual ferroelectric capacitor has an interfacial layer, and experiment always measures the sum of voltages across the interface layer and the ferroelectric layer. The main observation of decreasing ferroelectric capacitor voltage (V-F) for increasing ferroelectric capacitor charge (Q(F)), claimed to be the direct evidence for the NC effect, could be alternatively interpreted by either the sudden increase in the positive capacitance of a ferroelectric capacitor or decrease in the voltage across the interfacial layer due to resistance degradation. The experimental time-transient V-F and Q(F) could be precisely simulated by these alternative models that fundamentally assumes the reverse domain nucleation and growth. Supplementary experiments using an epitaxial BaTiO3 film supported this claim. This, however, does not necessarily mean that the realization of the NC effect within the ferroelectric layer is impractical under appropriate conditions. Rather, the circuit suggested by Khan et al. may not be useful to observe the NC effect directly. English NATURE PUBLISHING GROUP Alternative interpretations for decreasing voltage with increasing charge in ferroelectric capacitors Article 10.1038/srep20825 1 SCIENTIFIC REPORTS, v.6 SCIENTIFIC REPORTS 6 N scie scopus 000369899800001 2-s2.0-84958568101 Multidisciplinary Sciences Science & Technology - Other Topics Article NEGATIVE CAPACITANCE