Research
Post-doc research: Synthesizing new inorganic materials for better magnets, batteries, and semiconductors.
More details coming soon
Graduate research: Synthesizing new nitrogen-based ceramics (nitrides)
What are nitrides? What do they do?
Nitrides are solids that are made of metals chemically bonded to nitrogen (nominally in the form of N3- anions). The most widely used is probably gallium nitride (GaN, pictured) which enables high efficiency light emitting diodes (LEDs). The researchers who figured out how to precisely synthesize GaN semiconductors won the Nobel Prize in Physics in 2014 (Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura).
Nitrides are also useful as durable coatings and as superconductors, among other applications. A 2020 review article by Ann Greenaway and colleagues provides a nice overview of current and future applications for nitrides.
How can we discovery new nitrides?
Making nitrides is difficult for two main reasons:
nitrogen (N2, gas) is a very stable molecule, so getting it to react requires lots of energy and/or clever tricks.
oxygen (O2, gas) is more reactive than nitrogen, so oxygen must be rigorously excluded to prevent the formation of unwanted oxides / oxynitrides.
Traditionally, nitrides are made by heating the elements together to high temperatures (~1000 °C). However, this approach doesn't always work. Computational researchers have predicted many nitrides to be stable. My work focuses on finding clever ways to make these predicted nitrides.
One way that we have found to work is called metathesis reactions (also known as ion-exchange reactions). Importantly, this metathesis method succeeded in producing a compound, MgZrN2, that the traditional ceramic approach failed to yield. I presented this work as part of the 2021 #RSCPoster event on twitter (see below), and subsequently published my first first-author report in Chemistry of Materials. Our friends at NREL subsequently went on to show that our particular approach worked for a range of similar materials (check out their report here).
Publications
Post-doc research
Rom, C.L., O'Donnell, S., Huang, K., Klein, R.A., Kramer, M.J., Smaha, R.W., Zakutayev, A., "Bulk synthesis of Zn3WN4 via solid-state metathesis" 2024, https://doi.org/10.48550/arXiv.2401.01964
Graduate research
Rom, C.L., Novick, A., McDermott, M.J., Yakovenko, A.A., Gallawa, J.R., Tran, G.T., Asebiah, D.C., Storck, E.N., McBride, B.C., Miller, R.C., Prieto, A.L., Persson, K.A., Toberer, E., Stevanovic, Zakutayev, Neilson, "Mechanistically Guided Materials Chemistry: Synthesis of Ternary Nitrides, CaZrN2 and CaHfN2", J. Am. Chem. Soc. 2024, 146, 6, 4001–4012 https://doi.org/10.1021/jacs.3c12114
Rom, C.L., Smaha, R.W., Knebel, C.A., Heinselman, K.N., Neilson, J.R., Bauers, S.R., Zakutayev, "Bulk and film synthesis pathways to ternary magnesium tungsten nitrides", J. Mater. Chem. C, 2023, 11, 11451-11459 https://doi.org/10.1039/D3TC02059B
Rom, C.L., Smaha, R.W., Melamed, C.L., Schnepf, R.R., Heinselman, K.N., Mangum, J.S., Lee S.-J., Lany, S., Schelhas, L.T., Greenaway, A.L., Neilson, J.R., Bauers, S.R., Tamboli, A.C., Andrew, J.S.,"Combinatorial Synthesis of Cation-Disordered Manganese Tin Nitride MnSnN2 Thin Films with Magnetic and Semiconducting Properties" Chem. Mater. 2023, 35, 7, 2936–2946. https://doi.org/10.1021/acs.chemmater.2c03826
Rom, C.L. "Achieving Gender Equity in Academic Seminars" CSU Gold Papers, Winter 2023, 8, 3-5 https://goldpapers.colostate.edu/wp-content/uploads/sites/44/2023/02/2022-Winter-Edition-1.pdf
Culman, T.H., Woods-Robinson, R., Mangum, J.S., Smaha, R.W., Rom, C.L., Zakutayev, A. and Bauers, S.R., 2022. Nitrogen stabilizes the wurtzite polymorph in ZnSe1-xTex thin films. J. Mater. Chem. C. 2022, 10, 15806-15815. https://doi.org/10.1039/D2TC02716J
Todd, P.K., McDermott, M.J., Rom, C.L., Corrao, A.A., Denney, J.J., Dwaraknath, S.S., Khalifah, P.G., Persson, K.A. and Neilson, J.R., "Selectivity in Yttrium Manganese Oxide Synthesis via Local Chemical Potentials in Hyperdimensional Phase Space." Journal of the American Chemical Society, 2021, 143(37), 15185-15194. https://doi.org/10.1021/jacs.1c06229
Rom, C.L., Fallon, M.J., Wustrow, A., Prieto, A.L., Neilson, J.R. "Bulk Synthesis, Structure, and Electronic Properties of Magnesium Zirconium Nitride Solid Solutions", Chemistry of Materials, 2021, 33(13), 5345–5354. https://pubs.acs.org/doi/10.1021/acs.chemmater.1c01450
Rognerud, E.G., Rom, C.L., Todd, P.K., Singstock, N.R., Bartel, C.J., Holder, A.M., Neilson, J.R. "Kinetically Controlled Low-Temperature Solid-State Metathesis of Manganese Nitride Mn3N2", Chemistry of Materials, 2019, 31(18), 7248-7254. https://pubs.acs.org/doi/10.1021/acs.chemmater.9b01565
Undergraduate research
Vanagas, N.A., Wacker, J.N., Rom, C.L., Glass, E.N., Colliard, I., Qiao, Y., Bertke, J.A., Van Keuren, E., Schelter, E.J., Nyman, M., Knope, K.E. "Solution and Solid State Structural Chemistry of Th(IV) and U(IV) 4-Hydroxybenzoates", Inorganic Chemistry, 2018. 57(12), 7259-7269. https://pubs.acs.org/doi/10.1021/acs.inorgchem.8b00919
Levendorf, A.U., Chen, D., Rom, C.L., Liu, Y., Tong, Y. "Electrochemical and in situ ATR-SEIRAS investigations of methanol and CO electro-oxidation on PVP-free cubic and octahedral/tetrahedral Pt nanoparticles", RSC Advances, 2014. 4, 21284-21293. http://pubs.rsc.org/en/content/articlehtml/2014/ra/c4ra00815d