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Alberto Binetti

Publications and source records attributed to Alberto Binetti.

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Sub-unit cell engineering of CrVO$_3$ superlattice thin films

Ordered corundum oxides introduce new prospects in the field of functional oxides thin films, complementing the more widely studied class of ABO$_3$ perovskites. In this work, we take advantage of the layer-by-layer growth regime to fabricate epitaxial CrVO$_3$ superlattice thin films with atomic-scale accuracy on the periodic arrangement of Cr and V layers. By means of X-ray diffraction, scanning transmission electron microscopy and Raman spectroscopy, we confirm the thickness control in the sub-unit cell scale, alternating 3, 2 or 1 single atomic layers of Cr$_2$O$_3$ and V$_2$O$_3$. For the first time, we stabilize the ilmenite phase of CrVO$_3$ (space group R-3) and compare the functional properties of the thin film with those calculated by density functional theory. This novel approach to the growth of ordered corundum oxides opens the path towards the stabilization of new complex oxides with tailored properties by varying the composition and the superlattice period, ultimately broadening the family of functional rhombohedral oxides.

cond-mat.mtrl-sci

Blameocracy: Causal Rhetoric in Politics

This paper studies the supply and returns of causal rhetoric in politics: politicians' language linking political actions to outcomes through blame and credit. We fine-tune a language model to measure its use in 4.2 million congressional tweets spanning 2012--2023. Causal rhetoric is central to politicians' communication: it accounts for more than one third of tweets, is the language of political disagreement, and rises over time. The political returns of causal rhetoric are concentrated in blame. Combining campaign contributions with quasi-exogenous geographic variation in Twitter adoption, we find that exposure to blame has the largest effects on small donations. Using voting intentions from survey data and an event-study design around blame-only and credit-only days, we find that politicians' support rises in the week after blame-only days. Additional evidence suggests causal rhetoric, and especially blame, can turn complex economic mechanisms into underqualified yet plausible, politically convenient claims.

econ.GN

Confinement-Induced Isosymmetric Metal-Insulator Transition in Ultrathin Epitaxial V2O3 Films

Dimensional confinement has shown to be an effective strategy to tune competing degrees of freedom in complex oxides. Here, we achieved atomic layered growth of trigonal vanadium sesquioxide (V2O3) by means of oxygen-assisted molecular beam epitaxy. This led to a series of high-quality epitaxial ultrathin V2O3 films down to unit cell thickness, enabling the study of the intrinsic electron correlations upon confinement. By electrical and optical measurements, we demonstrate a dimensional confinement-induced metal-insulator transition in these ultrathin films. We shed light on the Mott-Hubbard nature of this transition, revealing an abrupt vanishing of the quasiparticle weight as demonstrated by photoemission spectroscopy. Furthermore, we prove that dimensional confinement acts as an effective out-of-plane stress. This highlights the structural component of correlated oxides in a confined architecture, while opening an avenue to control both in-plane and out-of-plane lattice components by epitaxial strain and confinement, respectively.

cond-mat.mtrl-sci