Electron beam recording of microdomains on the nonpolar LiNbO$_3$ crystal surface at different SEM accelerating voltages

The effect of the accelerating voltage $U$ of the SEM electron beam on the characteristics of microdomains recorded by the electron beam method on the nonpolar $Y$-surface of LiNbO$_3$ crystals has been studied. The thickness $T_d$ of domains in the $Y$ direction is determined by the depth range $R_e$ of primary electrons, which depends on $U$. This makes it possible to define $T_d$ in the range of 0.2–4 $\mu$m at $U$ = 5–25 kV, respectively. The electron emission coefficient $\sigma$ is estimated for different values of $U$ exceeding the second equilibrium point $U_2$ $(\sigma = 1)$ in the $\sigma(U)$ diagram. These data are used to construct the dependence $\sigma(U)$ for LiNbO$_3$. Based on the exposure characteristics of the length $L_d$ of domains growing along the polar $Z$ axis, the dependence of the space charge field controlling the domain planar growth along $Z$ on the surface electron emission $\sigma$ is found.