Prediction and Kinetic Stabilization of Sn(II)-Perovskite Oxide Nanoshells

• DOI: 10.1021/acs.chemmater.2c02192
• Publication Date: 2022-08-30T11:42:35Z
• Authors: Shaun O’Donnell; D. J. Osborn; Gowri Krishnan; Theresa Block; Aylin Koldemir; Thomas D. Small; Rachel Broughton; Jacob L. Jones; Rainer Pöttgen; Gunther G. Andersson; Gregory F. Metha; Paul A. Maggard
• Keywords: Nanoshell

The synthesis of kinetically stabilized, i.e., metastable, dielectric semiconductors, represents a major frontier within technologically important fields as compared to thermodynamically stable solids that have received considerably more attention. Of long-standing theoretical interest are Sn(II) perovskites [e.g., Sn(Zr1/2Ti1/2)O3 (SZT)], which isoelectronic Pb-free analogues Pb(Zr1/2Ti1/2)O3 (PZT), commercial piezoelectric composition is dominant in the electronics industry. Herein, we describe this metastable SZT through low-temperature flux reaction technique. has been found, for first time, grow and be stabilized nanoshell at surfaces Ba(Zr1/2Ti1/2)O3 (BZT) particles, forming BZT–SZT core–shell result cation exchange. In situ powder X-ray diffraction (XRD) transmission electron microscopy data show nanoshells from controlled diffusion cations into BZT with tunable thicknesses ∼25–100 nm. calculated possess metastability approximately −0.5 eV atom–1 respect decomposition SnO, ZrO2, TiO2 cannot currently prepared stand-alone particles. Rietveld refinements XRD consistent two-phase model, each phase possessing generally cubic perovskite-type structure nearly identical lattice parameters. Mössbauer spectroscopic (119Sn) an outer ∼5–10 nm surface region comprised oxidized Sn(IV) exposure air water. optical band gap shell was found ∼2.2 eV, red-shifted by ∼1.2 BZT. This closing probed photoelectron spectroscopy stem shift valence edge higher energies (∼1.07 eV) addition Sn 5s2 orbitals new higher-energy band. summary, novel synthetic tactic demonstrated effective preparing representing useful strategy kinetic stabilization other predicted, dielectrics.