Experimental and theoretical study of solid–solid dendrite domain growth in uniaxial ferroelectrics

Dendrite patterns appear in a wide range of natural phenomena, from metal castings to bacterial colonies and snowflakes. Significant efforts have been devoted to creating new experimental systems demonstrating dendrite growth that can be used as models for deep experimental study of the process. Here, we show the formation of ferroelectric dendrite domains during polarization reversal under nonequilibrium conditions. We achieved dendrite growth in lithium niobate LiNbO3 crystals with an artificial surface dielectric layer at elevated temperatures. The nonequilibrium switching conditions caused by incomplete screening of the depolarization field suppress the usual faceted domain growth. Up to six branching generations were observed, with a branch width below 100 nm. In situ optical imaging allowed dendrite evolution to be studied at millisecond temporal resolution. Our investigation into dendrite formation was based on an analogy between crystal and domain growth. Upon development of a corresponding computational model, we demonstrated that uniaxial ferroelectrics represent a promising model system for the experimental study of dendrite growth. Likewise, a wide range of driving parameters and a high spatial resolution help provide new insights into the general laws of the formation of dendrite patterns.