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The unique redox properties and high oxygen capacity of nanostructured CeO₂demonstrate a wide range of applications, such as electrolytes for solid oxide fuel cells, gas sensors, and catalysis for automotive exhaust gas. Most CeO₂nanomaterials are prepared by chemical synthesis or hard templating methods. An effective way to obtain highly textured, small‐radius dimensions with high specific surface area remains challenging. Here, highly textured CeO₂nanostructures with various shapes ranging from nanowires to nanoporous thin films are successfully synthesized. Vertically aligned nanocomposites (VANs) of Sr₃Al₂O₆(SAO) and CeO₂are synthesized first while varying concentration ratio between them. Once the SAO is dissolved in water, the remaining CeO₂forms distinct nanostructures. The thermal stability of the nanostructured CeO₂is evaluated byin situheating XRD and thermal annealing tests. This method provides an alternative approach to preparing nanostructured CeO₂without toxic chemical solutions or complex micro/nanofabrication techniques. These results present a novel approach to prepare nanostructured CeO₂for future sensing and energy device applications. 

Abstract Mott insulator VO₂exhibits an ultrafast and reversible semiconductor‐to‐metal transition (SMT) near 340 K (67 °C). In order to fulfill the multifunctional device applications, effective transition temperature (T_c) tuning as well as integrated functionality in VO₂is desired. In this study, multifunctionalities including tailorable SMT characteristics, ferromagnetic (FM) integration, and magneto‐optical (MO) coupling, have been demonstrated via metal/VO₂nanocomposite designs with controlled morphology, i.e., a two‐phase Ni/VO₂pillar‐in‐matrix geometry and a three‐phase Au/Ni/VO₂particle‐in‐matrix geometry. EvidentT_creduction of 20.4 to 54.9 K has been achieved by morphology engineering. Interestingly, the Au/Ni/VO₂film achieves a record‐lowT_cof 295.2 K (22.2 °C), slightly below room temperature (25 °C). The change in film morphology is also correlated with unique property tuning. Highly anisotropic magnetic and optical properties have been demonstrated in Ni/VO₂film, whereas Au/Ni/VO₂film exhibits isotropic properties because of the uniform distribution of Au/Ni nanoparticles. Furthermore, a strong MO coupling with enhanced magnetic coercivity and anisotropy is demonstrated for both films, indicating great potential for optically active property tuning. This demonstration opens exciting opportunities for the VO₂‐based device implementation towards smart windows, next‐generation optical‐coupled switches, and spintronic devices.