Microstructural evolution and ferroelectricity in HfO2 films

Ferroelectric (FE) materials, which typically adopt the perovskite structure with non-centrosymmetry and exhibit spontaneous polarization, are promising for applications in memory, electromechanical energy storage devices. However, these advanced suffer from intrinsic limitations of FEs, including poor complementary metal oxide semiconductor (CMOS) compatibility environmental issues associated lead. Hafnium (HfO2), stable bulk centrosymmetric phases, possesses robust ferroelectricity nanoscale thin films due to formation non-centrosymmetric phases. Owing its high CMOS scalability, HfO2 has attracted significant attention. In last decade, efforts have been made explore origin factors that influence FE properties films, particularly regarding role microstructure, is vital clarifying issues. Although several comprehensive reviews published, there currently no review focused on relationship between microstructure properties. This focuses microstructure-property relationships polycrystalline epitaxial films. The crystallographic structures characterization methods polymorphs first discussed. For microstructure-FE relationships, driving force kinetic pathway phase transformations under growth parameters or external stimuli reviewed. lattice matching relations substrates corresponding impact compared based their different microstructural characteristics. Finally, a future perspective given further investigating