@article{horgan_hsain_jones_grieger_2023, title={Development and application of screening-level risk analysis for emerging materials}, volume={35}, ISSN={2214-9937}, url={http://dx.doi.org/10.1016/j.susmat.2022.e00524}, DOI={10.1016/j.susmat.2022.e00524}, abstractNote={Analysis of a material's impact on society is increasingly recognized as a necessary step in materials development, especially in the area of lead-free piezoelectrics. Evaluations of the environmental, health, and societal impacts that occur throughout the material's life cycle are critical for determining the viability of lead-free alternatives. Risk screening approaches, such as the screening-level Emerging Materials Risk Analysis (EMRA) proposed in this work, may help researchers compare materials or material production routes to determine more sustainable solutions. As a first demonstration of its utility in the development of lead-free piezoelectrics, the approach introduced in this paper is applied to piezoelectric HfO2 (hafnia) to compare mining and processing routes and to elucidate the more sustainable route for HfO2 production. This paper aims to exemplify how the EMRA risk screening approach incorporates perspectives on environmental, health, and societal impacts into the materials research process by providing a relative risk screening evaluation of different material processing routes and/or different materials. Results from applying EMRA to hafnia show that the major known environmental impacts of hafnia mining and processing involve ecosystem destruction and heavy use of fossil fuels and electricity; health impacts related to potentially unsafe working conditions and potential exposure to radioactive elements; and societal impacts including land disputes and supply concerns. Results also demonstrate that the more sustainable production route currently available includes commercial wet mining with land rehabilitation followed by beneficiation via wet processes with consistent personal protective equipment use and water recycling. Almost all of the previously-mentioned impacts are avoided in this life cycle route. Outcomes from this analysis identify hafnia as a potentially sustainable replacement for certain applications of PZT and therefore encourage continued development of the material. Future efforts will test EMRA on a wide variety of other materials and revise the approach accordingly.}, journal={Sustainable Materials and Technologies}, publisher={Elsevier BV}, author={Horgan, Madison D. and Hsain, H. Alex and Jones, Jacob L. and Grieger, Khara D.}, year={2023}, month={Apr}, pages={e00524} }
 @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{horgan_2021, title={Biased decision making in materials science: Where does it originate and can it be avoided?}, volume={46}, ISSN={["1938-1425"]}, DOI={10.1557/s43577-021-00104-5}, number={5}, journal={MRS BULLETIN}, author={Horgan, Madison}, year={2021}, month={May}, pages={361–367} }
 @article{lee_hsain_fields_jaszewski_horgan_edgington_ihlefeld_parsons_jones_2021, title={Unexpectedly large remanent polarization of Hf0.5Zr0.5O2 metal-ferroelectric-metal capacitor fabricated without breaking vacuum}, volume={118}, ISSN={["1077-3118"]}, url={https://doi.org/10.1063/5.0029532}, DOI={10.1063/5.0029532}, abstractNote={We introduce an Atomic Layer Deposition (ALD) technique referred to here as Sequential, No-Atmosphere Processing (SNAP) to fabricate ferroelectric Hf0.5Zr0.5O2 capacitors in Metal–Ferroelectric–Metal (MFM) structures. SNAP involves the ALD of each layer sequentially while maintaining the sample under vacuum process conditions without ambient exposure during the entire sequential deposition processes. We first use plasma enhanced ALD to fabricate 002-textured TiN films and study the degree of texture and quality of the film by X-ray Diffraction (XRD), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), and transmission electron microscopy. Building upon the textured TiN film, we fabricate MFM capacitors with 10-nm-thick Hf0.5Zr0.5O2 via SNAP deposition and observe an unexpectedly large remanent polarization (2Pr = 54.2 μC/cm2). We report that annealing at T <800 °C and at T = 800 °C results in different ferroelectric behaviors and phases determined by grazing incidence XRD patterns. We infer that the nonpolar tetragonal phase is dominant in films treated at T <800 °C, whereas the polar orthorhombic phase is dominant in films treated at T = 800 °C. Using ToF-SIMS and x-ray spectroscopy depth profiling on MFM capacitors, we observe an increase in the concentration of defects in the Hf0.5Zr0.5O2 layer after annealing. We believe that the absence of the native passive layer between Hf0.5Zr0.5O2 and TiN layers made via SNAP deposition is responsible for the unexpectedly large remanent polarization. In addition, we associate the 002-textured TiN as potentially playing a role in realizing the unexpectedly large remanent polarization.}, number={1}, journal={APPLIED PHYSICS LETTERS}, author={Lee, Younghwan and Hsain, H. Alex and Fields, Shelby S. and Jaszewski, Samantha T. and Horgan, Madison D. and Edgington, Patrick G. and Ihlefeld, Jon F. and Parsons, Gregory N. and Jones, Jacob L.}, year={2021}, month={Jan} }