About

Daniel P. Shoemaker is an Associate Professor in the Department of Materials Science and Engineering and a Racheff Faculty Fellow. He is also an affiliate of the Department of Physics and the Illinois Quantum Information Science and Technology Center (IQUIST) at the University of Illinois. His academic background includes a PhD in Materials from the University of California, Santa Barbara, completed in 2010, and a BS in Materials Science and Engineering from the University of Illinois, earned in 2006. Prior to his current position, he conducted postdoctoral research at the Materials Science Division of Argonne National Laboratory. Professor Shoemaker's group focuses on the discovery and synthesis of electronic, magnetic, and quantum materials. He actively recruits postdoctoral researchers and graduate students with expertise in synthesis, characterization, and computation, emphasizing inorganic synthesis, characterization, and modeling. His group provides opportunities for undergraduate students to engage in independent, high-impact research projects, fostering early involvement in materials science research.

Research topics

• Nanotechnology
• Chemical engineering
• Materials science
• Chemistry
• Organic chemistry
• Inorganic chemistry
• Combinatorial chemistry
• Physical chemistry

Selected publications

• Architect of New Materials: Celebrating the Pioneering Contributions of Prof. Mercouri G. Kanatzidis

  Chemistry of Materials · 2026-04-28

  articleCorresponding
  PublisherDOI

• Dynamic magneto-chiral instability in photoexcited tellurium

  Nature Physics · 2026-01-09 · 2 citations

  article
  PublisherDOI

• Dynamic magneto-chiral instability in photoexcited tellurium

  Nature Physics · 2026-01-09 · 1 citations

  preprintOpen access
  PublisherOA PDFDOI

• Unique Structure Type and Antiferromagnetic Ordering in Semiconducting Eu ₂ InSnP ₃

  Chemistry of Materials · 2025-08-13 · 1 citations

  articleSenior authorCorresponding

  Rare-earth-containing ternary pnictides formed with main group elements occupy a chemical space where they can span insulating to metallic behavior, and they often exhibit low-dimensional structures where magnetic ordering can be tuned by moderate fields. Investigating compounds between semimetallic EuIn2P2 and EuSn2P2 led to the formation of an ordered quaternary phase Eu2InSnP3, which forms in the orthorhombic space group Pnma. The Eu2+ ions in Eu2InSnP3 form a hollandite-like channeled matrix of edge-sharing EuP6 octahedra. These Eu2+ donate electrons to a [InSnP3]4– polyanion which exhibits a distinct In–Sn bond to maintain charge balance in the Zintl framework. This bonding requirement and our experimental synthesis attempts with varying stoichiometries indicate that the In and Sn are fully ordered, leading to semiconducting behavior. First-principles simulations find the smallest band gap to be indirect of about 0.5 eV, but close in energy to a direct gap. The magnetic behavior of Eu2InSnP3 shows a low-field antiferromagnetic ordering at TN = 12 K and a spin-flop transition around 0.8 T at 2 K. The progression of magnetic states is complex, but can be ascertained by considering the connectivity of the two inequivalent magnetic sites in the compound and the low anisotropy of the 4f7 Eu2+ ion. In all, the ability of covalent In–Sn bonding to open a semiconducting gap is evidence of the delicate interactions in these compounds and their propensity to exhibit uncommon structural motifs.

  PublisherDOI

• Chemical Substitution and Band Gap Tunability in Chiral Ag ₃ Au(Se,Te) ₂ Solid Solutions

  The Journal of Physical Chemistry C · 2025-03-13 · 1 citations

  articleOpen accessSenior authorCorresponding

  Ag3AuSe2 and Ag3AuTe2 were previously predicted to be narrow direct gap semiconductors with the same chiral structure type. Recent computational studies using the Perdew–Burke–Ernzerhof (PBE) functional highlighted their potential band gap tunability via strain application. For example, Ag3AuSe2 was predicted to exhibit full band closure above 4% tensile strain. In this study, we explored chemical substitution to examine the density functional theory (DFT) predictions by replacing Se2– with larger Te2– anions. We synthesized and characterized the electronic and optical properties of Ag3Au(Se1–xTex)2 solid solutions for x from 0 to 1. Our findings revealed that the lattice constants increase linearly with Te incorporation, reaching 3.6% expansion at 90% Se2– to Te2– substitution. The activation energy and optical band gap of Ag3Au(Se,Te)2 were determined by using electrical resistivity and ultraviolet–visible (UV–vis) diffuse reflectance measurements. The band gap decreased with increasing Te content, although hybrid functionals are necessary to correctly predict the gap. Further computational studies on the band structures of Ag3Au(Se,Te)2 alloys would shed light on the impact of lattice parameter modification via chemical substitution on the band gap tunability.

  PublisherOA PDFDOI

• Narrow Optical Linewidths in Stoichiometric Layered Rare-Earth Crystals

  Physical Review Letters · 2025-05-27 · 1 citations

  article

  Rare-earth emitters in solids are well suited for implementing efficient, long-lived quantum memory coupled to integrated photonics for scalable quantum technologies. They are typically introduced as dopants in a solid-state host, but this introduces disorder and limits the available density of emitters. Stoichiometric materials can offer high densities with narrow optical linewidths. The regular spacing of emitters also opens possibilities for quantum information processing and collective effects. Here, we show narrow optical linewidths in a layered stoichiometric crystalline material, NaEu(IO_{3})_{4}. We observed an inhomogeneous linewidth of 2.2(1) GHz and a homogeneous linewidth of 120(4) kHz. Using spectral hole-burning techniques, we observe a hyperfine spin lifetime of 1.9(4) s. Furthermore, we demonstrate an atomic frequency comb delay of up to 800 ns.

  PublisherDOI

• Synthesis and optical quantum memory characterization of α-Eu(IO3)3, β-Eu(IO3)3, and NaEu(IO3)4

  ChemRxiv · 2025-10-21 · 1 citations

  preprintSenior author

  Three phases of stoichiometric europium (III) iodate compounds are probed as candidates for optical quantum memory to determine the impact of reaction conditions on phase formation and relate crystal structure to their ability to host persistent excited states relevant to quantum memory. Hydrothermal synthesis procedures for growing macroscopic single crystals of rectangular-block α-Eu(IO3)3 (P 21/c), yellow hexagonal plate β-Eu(IO3)3 (P 21/n), and transparent plate NaEu(IO3)4 are presented. The ability to burn narrow and long-lived spectral holes on the 7F0 →5 D0 optical transitions is a necessary condition for implementing optical quantum memory. α- Eu(IO3)3 was determined to be incapable of hole-burning due to the presence of insufficient site asymmetry of the europium site, which forbids the required optical transition. β-Eu(IO3)3 was determined to be incapable of storing information due to a lack of observed spectral hole burning, likely caused by decoherence due to the closely-packed edge-sharing Eu(III) polyhedra. Analysis of each phase’s crystal structure suggests that the Eu-Eu nearest neighbor distance and distortion of europium site symmetry are critical material design parameters for quantum memory applications.

  PublisherDOI

• Applied-field magnetic structure and spectroscopy shifts of the effective spin-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mfrac><mml:mn>1</mml:mn><mml:mn>2</mml:mn></mml:mfrac></mml:math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>X</mml:mi><mml:mi>Y</mml:mi></mml:mrow></mml:math>-like magnet <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Li</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>CoCl</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>

  Physical review. B./Physical review. B · 2025-08-19

  articleOpen accessSenior author

  Insulators containing chains of magnetic transition metal cations provide platforms for probing spin-$\frac{1}{2}$ dynamics and quantum critical behavior. ${\mathrm{Li}}_{2}{\mathrm{CoCl}}_{4}$ contains edge-sharing ${\mathrm{CoCl}}_{6}$ octahedra that form chains along the crystallographic $c$ axis and orders antiferromagnetically at zero field, but questions remain about its applied-field magnetic structure and the ${\mathrm{Co}}^{2+}$ spin state. Here, we show with neutron diffraction on a polycrystalline sample how the antialigned chains of cobalt moments begin to transition to a ferromagnetic state above 1.6 T. Further, using magnetic resonance absorption measurements and noninteracting spin models, we reveal the strongly anisotropic nature of the ${\mathrm{Co}}^{2+}$ ion's $XY$-like magnetic behavior (${g}_{\ensuremath{\parallel}}=2.77$ and ${g}_{\ensuremath{\perp}}=5.23$) and its $J=\frac{1}{2}$ ground state. We therefore supply the magnetic structures and anisotropic description needed to explore the dynamics of the field-driven magnetic phases, laying the foundation for further experimental and theoretical studies.

  PublisherOA PDFDOI

• Synthesis and optical quantum memory characterization of α-Eu(IO3)3, β-Eu(IO3)3, and NaEu(IO3)4

  ChemRxiv · 2025-10-07

  articleOpen accessSenior author

  Three phases of stoichiometric europium (III) iodate compounds are probed as candidates for optical quantum memory to determine the impact of reaction conditions on phase formation and relate crystal structure to their ability to host persistent excited states relevant to quantum memory. Hydrothermal synthesis procedures for growing macroscopic single crystals of rectangular-block α -Eu(IO 3 ) 3 ( P 2 1 / c ), yellow hexagonal plate β -Eu(IO 3 ) 3 ( P 2 1 /n), and transparent plate NaEu(IO 3 ) 4 are presented. The ability to burn narrow and long-lived spectral holes on the 7 F 0 → 5 D 0 optical transitions is a necessary condition for implementing optical quantum memory. α - Eu(IO 3 ) 3 was determined to be incapable of hole-burning due to the presence of insufficient site asymmetry of the europium site, which forbids the required optical transition. β -Eu(IO 3 ) 3 was determined to be incapable of storing information due to a lack of observed spectral hole burning, likely caused by decoherence due to the closely-packed edge-sharing Eu(III) polyhedra. Analysis of each phase’s crystal structure suggests that the Eu-Eu nearest neighbor distance and distortion of europium site symmetry are critical material design parameters for quantum memory applications.

  PublisherOA PDFDOI

• Synthesis of Layered Gold Tellurides AuSbTe and Au₂Te₃ and Their Semiconducting and Metallic Behavior

  Inorganic Chemistry · 2025-01-22 · 1 citations

  articleSenior authorCorresponding

  Previous studies on natural samples of pampaloite (AuSbTe) revealed the crystal structure of a potentially cleavable and/or exfoliable material, while studies on natural and synthetic montbrayite (Sb-containing Au2Te3) claimed various chemical compositions for this low-symmetry compound. Few investigations of synthetic samples have been reported for both materials, leaving much of their chemical, thermal, and electronic characteristics unknown. Here, we investigate the stability, electronic properties, and synthesis of the gold antimony tellurides AuSbTe and Au1.9Sb0.46Te2.64 (montbrayite). Differential thermal analysis and in situ powder X-ray diffraction revealed that AuSbTe is incongruently melting, while Au1.9Sb0.46Te2.64 is congruently melting. Calculations of the band structures and four-point resistivity measurements showed that AuSbTe is a semiconductor and Au1.9Sb0.46Te2.64 a metal. Various synthesis attempts confirmed the limited stable chemical composition of Au1.9Sb0.46Te2.64, identified successful methods to synthesize both compounds, and highlighted the challenges associated with single-crystal synthesis of AuSbTe.

  PublisherDOI

Recent grants

• SEP Collaborative: Routes to Earth Abundant Kesterite-based Thin Film Photovoltaic Materials

  NSF · $320k · 2012–2017

Frequent coauthors

• André Schleife

  National Center for Supercomputing Applications

  45 shared

• Zachary W. Riedel

  25 shared

• Manohar H. Karigerasi

  University of Illinois System

  21 shared

• Ankita Bhutani

  20 shared

• Mercouri G. Kanatzidis

  Northwestern University

  19 shared

• Kejian Qu

  University of Illinois Urbana-Champaign

  18 shared

• Ram Seshadri

  University of California, Santa Barbara

  18 shared

• Rebecca D. McAuliffe

  Oak Ridge National Laboratory

  17 shared

Labs

• Shoemaker GroupPI

  Discovery and Synthesis of Electronic, Magnetic, and Quantum Materials

Education

• PhD, Materials

  University of California Santa Barbara

  2010

• BS, Materials Science and Engineering

  University of Illinois at Urbana-Champaign

  2006

Awards & honors

• University of Illinois Campus Award for Excellence in Underg…
• Engineering Council Outstanding Advising Award (March 2020)
• 2017 Ivan Racheff Fellow Award (2017)
• DOE Early Career Award (2015)
• 23rd Louis Rosen Thesis Prize - Los Alamos Neutron Science C…