Stabilization of metallic phase in V2O3 thin film

Abstract

The tailoring and understanding of the metal-insulator transitions (MITs) in vanadium sesquioxide, V2O3, is of major interest for both applications and fundamental physics. V2O3 has been characterized by MIT and concurrent structural transition at ∼155 K; however, the nature of the MIT has remained more elusive. We investigated the MIT and the electronic structure (in metallic phase) of the pulsed laser deposition grown strained vanadium sesquioxide thin films on Si. The strained thin films synthesized here show the suppression (by ∼23 K) of the MIT to lower temperatures, whilst the structural transition temperature decreases only by ∼10 K. Our results systematically confirm that albeit the structural changes are crucial in V2O3, electronic transition seems to be of Mott-Hubbard type. Stabilization of the metallic phase in the strained V2O3 thin film has been manifested from resistivity data and observations of the increased crystal field and quasiparticle features.

Robust Coupling between Structural and Electronic Transitions in a Mott Material

“…We applied these methods to strained films exhibiting large variations in transition temperatures. Contrary to previous work, [33][34][35] we find no signature of decoupling between the structural and electronic transitions, to our measurement resolution. Our findings provide a significant constraint for any theory aiming to explain the MIT in V2O3 and put forward important experimental considerations regarding the interpretation of similar measurements in V2O3, VO2, and other Mott materials.…”

“…More evidence for a structural precursor to the MIT was suggested from surface acoustic waves measurements [33] and Raman spectroscopy. [34] However, in the three latter studies the measured precursors were compared to the resistance, which is a poor indicator for the state of the sample, as we elucidate in the present work (see SI). Most recently, a near-field infra-red imaging study, combined with atomic force microscopy and x-ray diffraction (XRD), analyzed the evolution of the nanoscale domain structure of V2O3 thin films with temperature.…”

Uncovering the Mechanism of the Impurity-Selective Mott Transition in Paramagnetic V2O3

“…Our findings elucidate the major factors controlling the phase diagram of vanadium sesquioxide, and should also be relevant to interpret recent V 2 O 3 thin-film studies [36,37]. We furthermore observe that whereas these effects are importantly enhanced by electron correlations, the described trends appear already at the one-electron level within the static mean-field DFT+U framework.…”

Metal–Insulator Transitions in Stable V2O3 Thin Films: Atomic Layer Deposition and Postdeposition Annealing Studies

“…26-278), with preferred orientation of (006) plane at 2θ %38.64 and (0012) plane at %82.81 along with planes of c-sapphire. [27] The full width half maxima (FWHM) of (006) reflection of V 2 O 3 films decrease with increase in the film thickness due to an increase in the crystallinity and longrange ordering in the preferred direction (Figure S1, Supporting Information). The stability of the V 2 O 3 thin film (19,48, and 85 nm) films are shown in Figure S5 and S6, Supporting Information, respectively, which describe the gradual enhancement in the grain size growth with an increase in the film thickness.…”