Forced diffusion of correlated impurities in the Peierls conductor $o$-TaS$_3$

It is shown that in orthorhombic TaS$_3$ with quenching defects, when the temperature changes in the region below the Peierls transition temperature $T < T_{\mathrm{P}}$, forced diffusion of defects arises due to their strong interaction with the charge density wave (CDW). The relationships between the concentration of quenching defects, $n$, the threshold field of the onset of CDW sliding, $E_{\mathrm{T}}$, and the defect-induced shift of $T_{\mathrm{P}}$ are determined: $E_T \propto n$ and $\Delta T_P \propto n$. This set of laws corresponds to the case when quenching defects positions are correlated with the CDW. The ordinary (without thermocycling) diffusion of quenching defects was detected at $T \approx 300$ K, its diffusion coefficient and the height of the energy barrier were estimated. This made it possible to clarify the most probable nature of the defects. These are interstitial sulfur impurities introduced during quenching into the van der Waals gap between the chains and partially ordered at $T < T_{\mathrm{P}}$ due to interaction with the CDW. This ordering significantly lowers the height of the energy barrier of forced diffusion in comparison with ordinary diffusion when the spatial configuration of the CDW changes during thermocycling. This leads to the appearance of anomalously high low-temperature forced mobility of correlated impurities.