@article{broughton_o'donnell_gabilondo_newell_maggard_jones_2024, title={Superstructure reflections in 40% Sn(II)-substituted BaZr<sub>0.5</sub>Ti<sub>0.5</sub>O<sub>3</sub> perovskite modeled with a Bayesian method for crystallographic refinement}, volume={6}, ISSN={["1573-4803"]}, DOI={10.1007/s10853-024-09878-w}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Broughton, Rachel and O'Donnell, Shaun and Gabilondo, Eric and Newell, Ryan and Maggard, Paul A. and Jones, Jacob L.}, year={2024}, month={Jun} }
 @article{gabilondo_odonnell_jana_broughton_liang_koldemir_reichling_campbell_halasyamani_poettgen_et al._2024, title={Unveiling Stability Factors in Sn(II)-Containing Oxides: Discovery of a Polar Tin Titanate and Photocatalytic Activity for Overall Water Splitting}, volume={5}, ISSN={["1520-5002"]}, DOI={10.1021/acs.chemmater.4c00929}, abstractNote={The discovery of Sn(II)-containing oxide semiconductors has been severely limited by a lack of understanding of the factors leading to their thermodynamic stability, e.g., chemical compositions and structure types, as well as by the absence of productive synthetic routes. The relatively few reported Sn(II)–O–M (M = early transition-metal cation) semiconductors frequently decompose at moderate to low temperatures. Herein, a large-scale predictive modeling approach was used to assess the structural factors yielding their enhanced thermodynamic stability. This has resulted in 10 new predicted Sn(II)-containing oxides that are proposed to fall within reasonable synthetic limits. Increasing stability was found for structures possessing lower Sn(II)/M ratios and local asymmetric coordination environments allowing the expression of the Sn(II) stereoactive lone pair. As a test of these results, synthetic efforts to prepare one of the proposed compounds starting from BaLa4Ti4O15 yielded the predicted layered-perovskite SnLa4Ti4O15 (SLTO). The new SLTO crystallizes in the noncentrosymmetric and polar P3c1 space group (no. 158) as confirmed by Rietveld refinements of powder X-ray diffraction (XRD) data and second harmonic generation activity. Full Sn(II) substitution was confirmed by a combination of XRD structural refinements, 119Sn Mössbauer spectroscopy, SEM-EDS, and X-ray photoelectron spectroscopy. UV–vis diffuse reflectance data confirmed that SLTO has a visible-light absorbing band gap of ∼2.4 eV and is a promising photocatalyst for solar energy conversion. After loading its surfaces with a Rh/Cr2O3–CoOx dual-cocatalyst, SLTO with hexagonal plate-shaped morphologies showed activity for overall water splitting at a rate of ∼317 μmol g–1 h–1 H2 and an apparent quantum yield of ∼22%. Thus, these results highlight the synergistic combination of chemical intuition, predictive modeling, and synthetic design in the synthesis of new Sn(II)-containing semiconductors for promising applications of their optical properties and photocatalytic activities for water splitting.}, journal={CHEMISTRY OF MATERIALS}, author={Gabilondo, Eric A. and ODonnell, Shaun and Jana, Subhendu and Broughton, Rachel and Liang, Mingli and Koldemir, Aylin and Reichling, Jack and Campbell, Carson and Halasyamani, P. Shiv and Poettgen, Rainer and et al.}, year={2024}, month={May} }
 @article{gabilondo_newell_broughton_koldemir_poettgen_jones_maggard_2023, title={Switching Lead for Tin in PbHfO<sub>3</sub>: Noncubic Structure of SnHfO<sub>3</sub>}, volume={9}, ISSN={["1521-3773"]}, DOI={10.1002/anie.202312130}, abstractNote={Abstract}, journal={ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, author={Gabilondo, Eric A. and Newell, Ryan J. and Broughton, Rachel and Koldemir, Aylin and Poettgen, Rainer and Jones, Jacob L. and Maggard, Paul A.}, year={2023}, month={Sep} }
 @article{o'donnell_osborn_krishnan_block_koldemir_small_broughton_jones_pottgen_andersson_et al._2022, title={Prediction and Kinetic Stabilization of Sn(II)-Perovskite Oxide Nanoshells}, volume={8}, ISSN={["1520-5002"]}, DOI={10.1021/acs.chemmater.2c02192}, abstractNote={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 are isoelectronic Pb-free analogues of Pb(Zr1/2Ti1/2)O3 (PZT), a commercial piezoelectric composition that is dominant in the electronics industry. Herein, we describe the synthesis of this metastable SZT dielectric through a low-temperature flux reaction technique. The SZT has been found, for the first time, to grow and to be stabilized as a nanoshell at the surfaces of Ba(Zr1/2Ti1/2)O3 (BZT) particles, i.e., forming as BZT–SZT core–shell particles, as a result of Sn(II) cation exchange. In situ powder X-ray diffraction (XRD) and transmission electron microscopy data show that the SZT nanoshells result from the controlled cation diffusion of Sn(II) cations into the BZT particles, with tunable thicknesses of ∼25–100 nm. The SZT nanoshell is calculated to possess a metastability of approximately −0.5 eV atom–1 with respect to decomposition to SnO, ZrO2, and TiO2 and cannot currently be prepared as stand-alone particles. Rietveld refinements of the XRD data are consistent with a two-phase BZT–SZT model, with each phase possessing a generally cubic perovskite-type structure and nearly identical lattice parameters. Mössbauer spectroscopic data (119Sn) are consistent with Sn(II) cations within the SZT nanoshells and an outer ∼5–10 nm surface region comprised of oxidized Sn(IV) cations from exposure to air and water. The optical band gap of the SZT shell was found to be ∼2.2 eV, which is red-shifted by ∼1.2 eV compared to that of BZT. This closing of the band gap was probed by X-ray photoelectron spectroscopy and found to stem from a shift of the valence band edge to higher energies (∼1.07 eV) as a result of the addition of the Sn 5s2 orbitals forming a new higher-energy valence band. In summary, a novel synthetic tactic is demonstrated to be effective in preparing metastable SZT and representing a generally useful strategy for the kinetic stabilization of other predicted, metastable dielectrics.}, journal={CHEMISTRY OF MATERIALS}, author={O'Donnell, Shaun and Osborn, D. J. and Krishnan, Gowri and Block, Theresa and Koldemir, Aylin and Small, Thomas D. and Broughton, Rachel and Jones, Jacob L. and Pottgen, Rainer and Andersson, Gunther G. and et al.}, year={2022}, month={Aug} }
 @article{gabilondo_o'donnell_newell_broughton_mateus_jones_maggard_2022, title={Renaissance of Topotactic Ion-Exchange for Functional Solids with Close Packed Structures}, volume={4}, ISSN={["1521-3765"]}, DOI={10.1002/chem.202200479}, abstractNote={Abstract}, journal={CHEMISTRY-A EUROPEAN JOURNAL}, author={Gabilondo, Eric and O'Donnell, Shaun and Newell, Ryan and Broughton, Rachel and Mateus, Marcelo and Jones, Jacob L. and Maggard, Paul A.}, year={2022}, month={Apr} }
 @article{wohninsland_fetzer_broughton_jones_lalitha_2022, title={Structural and microstructural description of relaxor-ferroelectric transition in quenched Na1/2Bi1/2TiO3-BaTiO3}, volume={8}, ISSN={["2352-8478"]}, DOI={10.1016/j.jmat.2022.01.006}, abstractNote={Quenching lead-free Na1/2Bi1/2TiO3-based ceramics from sintering temperature is established to increase the depolarization temperature, Td and the lattice distortion. In situ synchrotron X-ray diffraction measurements were carried out on furnace cooled and quenched Na1/2Bi1/2TiO3 - BaTiO3 (NBT-BT) with 6 and 9 mol. % BT to discern the field-induced ferroelectric order. Phase fractions were determined from full pattern Rietveld refinements and utilized together with the change in unit cell volume to calculate volumetric strain resulting from phase transformations. NBT-6BT demonstrates a cubic symmetry in the furnace cooled state but quenching stabilizes the rhombohedral R3c phase and delays the formation of a field-induced, long range-ordered tetragonal phase, thereby shifting the onset of macroscopic strain to higher fields. A field-induced phase transition from a weakly distorted rhombohedral to tetragonal phase can be observed in furnace cooled NBT-9BT. However, this phase transition cannot be detected in quenched NBT-9BT, since the ferroelectric tetragonal P4mm phase is stabilized in the initial state. In contrast to the furnace cooled materials, both the quenched compositions exhibit overall negligible volumetric strain as a function of electric field. Furthermore, scanning electron micrographs of chemically etched, poled and unpoled samples reveal an increased lamellar domain contrast in the quenched materials. All these findings strengthen the hypothesis of a stabilized ferroelectric order resulting in the absence of a field-induced phase transformation in quenched NBT-BT.}, number={4}, journal={JOURNAL OF MATERIOMICS}, author={Wohninsland, Andreas and Fetzer, Ann-Katrin and Broughton, Rachel and Jones, Jacob L. and Lalitha, K. V.}, year={2022}, month={Jul}, pages={823–832} }
 @article{lee_broughton_hsain_song_edgington_horgan_dowden_bednar_lee_parsons_et al._2022, title={The influence of crystallographic texture on structural and electrical properties in ferroelectric Hf0.5Zr0.5O2}, volume={132}, ISSN={["1089-7550"]}, url={https://doi.org/10.1063/5.0128038}, DOI={10.1063/5.0128038}, abstractNote={Ferroelectric (Hf,Zr)O2 thin films have attracted increased interest from the ferroelectrics community and the semiconductor industry due to their ability to exhibit ferroelectricity at nanoscale dimensions. The properties and performance of the ferroelectric (Hf,Zr)O2 films generally depend on various factors such as surface energy (e.g., through grain size or thickness), defects (e.g., through dopants, oxygen vacancies, or impurities), electrodes, interface quality, and preferred crystallographic orientation (also known as crystallographic texture or simply texture) of grains and/or domains. Although some factors affecting properties and performance have been studied extensively, the effects of texture on the material properties are still not understood. Here, the influence of texture of the bottom electrode and Hf0.5Zr0.5O2 (HZO) films on properties and performance is reported. The uniqueness of this work is the use of a consistent deposition process known as Sequential, No-Atmosphere Processing (SNAP) that produces films with different preferred orientations yet minimal other differences. The results shown in this study provide both new insight on the importance of the bottom electrode texture and new fundamental processing-structure–property relationships for the HZO films.}, number={24}, journal={JOURNAL OF APPLIED PHYSICS}, author={Lee, Younghwan and Broughton, Rachel A. and Hsain, H. Alex and Song, Seung Keun and Edgington, Patrick G. and Horgan, Madison D. and Dowden, Amy and Bednar, Amanda and Lee, Dong Hyun and Parsons, Gregory N. and et al.}, year={2022}, month={Dec} }
 @article{gabilondo_o'donnell_broughton_jones_maggard_2021, title={Synthesis and stability of Sn(II)-containing perovskites: (Ba,Sn-II)(HfO3)-O-IV versus (Ba,Sn-II)(SnO3)-O-IV}, volume={302}, ISSN={["1095-726X"]}, DOI={10.1016/j.jssc.2021.122419}, abstractNote={While Sn(II)-containing perovskite oxides have long drawn attention as Pb(II) substitutes in technologically-relevant dielectric materials, they are also highly thermodynamically unstable and potentially impossible to prepare. Investigations into the new flux-mediated syntheses of metastable Sn(II)-containing hafnate and stannate perovskites were aimed at understanding the key factors related to their synthesizability. The BaHfO3 perovskite was reacted with SnClF from 250 to 350 ​°C for 12–72 ​h, yielding an unprecedented Sn(II) concentration on the A-site of up to ~70 ​mol%, i.e., (Ba0.3Sn0.7)HfO3 in high purity. Elemental mapping using EDS shows the Sn(II) cations diffuse gradually throughout the crystallites, with two reaction cycles needed to give a nearly homogeneous distribution. In contrast, similar reactions with BaSnO3 and as little as 10 ​mol% Sn(II) result in decomposition to SnO, SnO2, and BaSnO3. The (Ba1-xSnx)HfO3 compositions exhibit a primary cubic perovskite structure (Pm3¯m; for x ​= ​1/3, 1/2 and 2/3) by powder X-ray diffraction (XRD) methods, with the Sn(II) cations substituted on the A-site. Total energy calculations show the thermodynamic instability versus the ground state (i.e., metastability) for (Ba1-xSnx)HfO3 increases with Sn(II) substitution, reaching a maximum of ~446 ​meV atom−1 at ~70 ​mol% Sn(II). The decomposition pathway of (Ba1/3Sn2/3)HfO3 was probed by ex situ XRD as well as in situ electron microscopy methods. An onset of thermally-induced decomposition begins at ~350–400 ​°C to give the more stable oxides which are found to segregate out in surface layers. These results help to elucidate the factors underpinning the synthesizability of highly metastable Sn(II)-containing perovskites, which increases with their cohesive energy and with the absence of lower-energy polymorphs or other ground states that can be reached without significant ion diffusion.}, journal={JOURNAL OF SOLID STATE CHEMISTRY}, author={Gabilondo, Eric A. and O'Donnell, Shaun and Broughton, Rachel and Jones, Jacob L. and Maggard, Paul A.}, year={2021}, month={Oct} }
 @article{prah_dragomir_rojac_bencan_broughton_chung_jones_sherbondy_brennecka_ursic_2020, title={Strengthened relaxor behavior in (1-x)Pb(Fe0.5Nb0.5)O-3-xBiFeO(3)}, volume={8}, ISSN={["2050-7534"]}, DOI={10.1039/c9tc05883d}, abstractNote={A systematic study of (1−x)Pb(Fe0.5Nb0.5)O3–xBiFeO3 (x = 0–0.5) was performed in order to investigate the strengthening of the relaxor properties when adding BiFeO3 into Pb(Fe0.5Nb0.5)O3 and forming a solid solution.}, number={10}, journal={JOURNAL OF MATERIALS CHEMISTRY C}, author={Prah, Uros and Dragomir, Mirela and Rojac, Tadej and Bencan, Andreja and Broughton, Rachel and Chung, Ching-Chang and Jones, Jacob L. and Sherbondy, Rachel and Brennecka, Geoff and Ursic, Hana}, year={2020}, month={Mar}, pages={3452–3462} }
 @article{jones_broughton_iamsasri_fancher_wilson_reich_smith_2019, title={The use of Bayesian inference in the characterization of materials and thin films}, volume={75}, ISSN={["2053-2733"]}, DOI={10.1107/S0108767319097940}, journal={ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES}, author={Jones, Jacob L. and Broughton, Rachel and Iamsasri, Thanakorn and Fancher, Chris M. and Wilson, Alyson G. and Reich, Brian and Smith, Ralph C.}, year={2019}, pages={A211–A211} }