  Ferroelectric materials promise exceptional attributes including low power
dissipation, fast operational speeds, enhanced endurance, and superior
retention to revolutionize information technology. However, the practical
application of ferroelectric-semiconductor memory devices has been
significantly challenged by the incompatibility of traditional perovskite oxide
ferroelectrics with metal-oxide-semiconductor technology. Recent discoveries of
ferroelectricity in binary oxides such as Zn1-xMgxO and Hf1-xZrxO have been a
focal point of research in ferroelectric information technology. This work
investigates the ferroelectric properties of Zn1-xMgxO utilizing automated band
excitation piezoresponse force microscopy. Our findings reveal the coexistence
of two ferroelectric subsystems within Zn1-xMgxO. We propose a "fringing-ridge
mechanism" of polarization switching that is characterized by initial lateral
expansion of nucleation without significant propagation in depth, contradicting
the conventional domain growth process observed in ferroelectrics. This unique
polarization dynamics in Zn1-xMgxO suggests a new understanding of
ferroelectric behavior, contributing to both the fundamental science of
ferroelectrics and their application in information technology.
