Lag between resistance and diffraction responses with electrically driven oscillations in VO2/AlN/Si

Separating the insulator-to-metal transition (IMT) from the structural phase transition (SPT) in VO 2 is central to controlling correlated-oxide transitions; such control may be useful for terahertz-switching applications. We investigate the relative evolution of electronic transport and structure in VO 2 /AlN/Si. Independent resistance–temperature (R–T) measurements give T c,H = 347.5 K; paired R–T/X-ray diffraction (XRD) shows that the resistance decrease precedes the major evolution of the tracked out-of-plane diffraction peak, with an approximately 8.2 K difference between their operational midpoints. Separately paired Raman measurements reveal V–V mode softening and residual spectral weight during the resistance decrease, and ultraviolet photoelectron spectroscopy (UPS) shows an approximately 0.13 eV deeper occupied V 3d onset relative to the Al 2 O 3 -supported reference. Electrically driven oscillations demonstrate device operation under the stated circuit conditions. These observations are compatible with a Mott-assisted interpretation of electronic–lattice coupling. AlN-mediated strain remains a possible contributor motivated by prior characterization of this growth platform.