Effects of the Domain Wall Conductivity on the Domain Formation under AFM-Tip Voltages in Ion-Sliced LiNbO3 Films

Abstract

The specified domain patterns were written by AFM-tip voltages in LiNbO3 films composing LNOI (LiNbO3-on-insulator). The domain wall conductivity (DWC) was estimated in the written patterns. This estimate was based on the effects of load resistors RL inserted between DWs and the ground, on the features of occurring domains. In this case, the domain formation is controlled by the ratio between RL and the DWs’ resistance RDW. Starting from the comparison of patterns appearing at different RL, the value of RDW in a specified pattern was estimated. The corresponding DWC is of σDW ≈ 10−3 (Ohm cm)−1 which exceeds the tabular bulk conductivity of LiNbO3 by no less than twelve orders of magnitude. A small DW inclination angle of (10−4)0 responsible for this DWC is not caused by any external action and characterizes the domain frontal growth under an AFM-tip voltage.

Deepening of domains at e-beam writing on the −Z surface of lithium niobate

“…It should be noted that the PFM technique is commonly used to detect and study domains in ferroelectrics [34]. For example, domains on polar LN cuts, created by the AFM tip field, have a clearly visible contrast in the PFM mode [35]. At the same time, our own experience shows that the domains created by the e-beam on the polar negative LN cuts were not detected by the PFM.…”

Resistive switching properties in polycrystalline LiNbO3 thin films

“…DW DW s = where R DW denotes the total DWC resistance; w denotes the total width of the DWs; t denotes the DW thickness, which is assumed to be ∼20 nm; 8,26) L denotes the length of the DW that can be roughly replaced by the thickness of the poly-LNO film. Taking the grain boundaries as the DWs, according to the measured LRS of ∼100 Ω, the DWC was estimated as 1.2 × 10 −3 (Ω•cm) −1 , which is comparable to that estimated for single-crystal LNO films.…”

“…The measured low-resistance state (LRS) was as low as ∼100 Ω. According to a method developed by Radmir Gainutdinov, 26) a revised formula is provided below.…”

New Trends in Lithium Niobate: From Bulk to Nanocrystals

“…Among the contributions dealing with nonlinear optical applications of LN and LT in this Special Issue, papers using both traditional bulk crystals [14][15][16] and thin films on LNOI platform [17][18][19] can be found. All are concerned with internal electric fields resulting in nonlinear response, another topic of Prof. Schirmer.…”

“…Taking into account the enormous potential of LN thin films for integrated quantum photonics produced by the LNOI technology and comparable only to silicon-based photonics, progress in this field is of utmost interest. The contribution of Gainutdinov and Volk [17] addresses the problem of understanding and influencing the unique properties of nanodomains written by AFM-tip voltages in LN films formed on insulator structures where the electrical conductivity is essentially due to polaronic charges trapped by nanodomain walls.…”