About

Dr. Wei-Jung A. Chen is a Professor and Assistant Dean for Student Affairs at the Texas A&M University Naresh K. Vashisht College of Medicine, within the Department of Neuroscience & Experimental Therapeutics. His research interests include the effects of substance abuse, such as alcohol, cocaine, and nicotine, on the developing brain, as well as polydrug interactions impacting brain and cognitive development. He investigates fetal alcohol syndrome and employs various techniques including 3-dimensional stereological cell counting, immunohistochemistry, radioimmunoassay, high-performance liquid chromatography, and gas chromatography in animal models like rodents, ovine, and zebrafish. Dr. Chen participates in graduate training as a faculty member in the Interdisciplinary Program in Neuroscience. His contributions to the field have been recognized through awards such as the Presidential Professor for Teaching Excellence Award and the University-Level Distinguished Achievement Award conferred by Texas A&M University.

Research topics

• Nanotechnology
• Materials science
• Condensed matter physics
• Physics
• Optoelectronics
• Computer Science
• Optics
• Quantum mechanics
• Composite material
• Electronic engineering
• Chemical physics

Selected publications

• Ion‐Implantation, Epilayer Growth, and Lift‐Off of High‐Quality Diamond Films

  Advanced Functional Materials · 2025-04-30 · 5 citations

  articleOpen access

  Abstract The development of high‐quality diamond films is pivotal for driving advances in quantum technology, power electronics, and thermal management. The ion implantation and lift‐off technique has emerged as a crucial method for fabricating diamond films with controlled thickness and scalable production of large‐area diamond wafers. This study advances the understanding of critical interface dynamics during diamond epilayer growth on ion‐implanted commercial diamond substrates. Leveraging high‐resolution cross‐sectional electron microscopy and spectroscopic analyses, the direct transformation of the damaged diamond layer is revealed into a graphitic layer during epilayer overgrowth, eliminating the need for high‐temperature annealing. Raman and photoluminescence spectroscopy mappings along the side section highlight the exceptional quality and purity of the epilayer, showcasing nitrogen‐vacancy center densities comparable to electronic‐grade diamond, making it highly suitable for quantum and electronic applications. Finally, the epilayer detaches efficiently via electrochemical etching, leaving a substrate with low surface roughness that is reusable for multiple growth cycles. These results provide valuable insights into refining the ion implantation and lift‐off process, bridging critical gaps in interface evolution, and establishing a foundation for sustainable, high‐performance diamond films across diverse technological applications.

  PublisherOA PDFDOI

• The Impact of Superconducting Properties of Micron-Scale Masked Proton Irradiation on BaTiO3-Doped YBCO Film

  Quantum Beam Science · 2025-04-18 · 1 citations

  articleOpen access1st authorCorresponding

  This study investigates the effects of 60 keV proton irradiation on BaTiO3-doped YBa2Cu3O7−δ (YBCO) films using masks with micron-scale holes to create controlled defect patterns aimed at enhancing superconducting properties. Contrary to expectations, masked irradiation resulted in a reduction in the critical current density (Jc), while unmasked irradiation demonstrated improvement, consistent with previous studies. Notably, no improvement was observed at 2 T around liquid nitrogen temperature. These observations highlight the challenges of employing micron-scale masks in defect engineering and underscore the need for further refinement to achieve the desired performance enhancement. Insights from this study contribute to advancing defect engineering techniques for improving YBCO’s performance in high-field applications, including fusion energy systems.

  PublisherOA PDFDOI

• Active Microfluidic Mixing Using Photoacoustic Laser Streaming from Gold-Implanted Optical Fibers and Glass Beads

  The Journal of Physical Chemistry C · 2025-04-01 · 1 citations

  article

  Efficient microfluidic mixing remains a significant challenge due to the difficulty of generating advection and turbulence, especially as many applications demand reduced sample and reagent consumption for improved efficiency and lower costs. In this work, we introduce a new active mixing method─photoacoustic laser streaming (PALS)─which uses laser pulses to produce fluid jets. PALS integrates photoacoustic effects with acoustic streaming, transforming metal-coated surfaces into fluidic pumps without moving mechanical parts. To demonstrate the concept, we fabricated a fiber-based PALS pump by implanting gold (Au) onto the facet of an optical fiber. The fiber tip was immersed in liquids to perform mixing in a microplate (50 μL volume), achieving complete mixing in 3 min compared to hours required for diffusion alone. Additionally, we utilized Au-coated glass microbeads as PALS stirrers. Upon light excitation, the beads not only generated jets from their surfaces but were also recoiled by the jets, creating enhanced turbulence and more efficient mixing. While this method was demonstrated in a microplate, we anticipate even greater effectiveness in microfluidic channels, where traditional mixing techniques face significant limitations.

  PublisherDOI

• Temperature effects of ion irradiation on the nanostructural features in ductile-phase-toughened tungsten composites

  Journal of Applied Physics · 2025-05-22 · 2 citations

  articleOpen access

  Ductile-phase toughened tungsten (DPT W) composites have emerged as promising candidates for load-bearing components behind the plasma-facing tungsten armor in fusion reactors due to their enhanced thermomechanical properties. This study focuses on a composite consisting of W particles embedded in a ductile NiFeW solution matrix, hot-rolled to a thickness reduction of 87% (87R DPT W). Sequential irradiations with Ni2+ and He+ ions were performed to identical doses and helium concentrations at room temperature (RT) and 1273 K. Irradiation at RT produced no discernible nanostructural features due to the immobility of mono-vacancies, whereas cavity formation was observed at 973 K. At 1273 K, the W phase exhibited larger cavities, reduced cavity number density, and lower volumetric swelling compared to 973 K. Notably, nanosized NiFeW precipitates formed within the W phase at 1273 K, a phenomenon absent at 973 K. A new phase of cubic (NiFe)6W6C was also observed at the interphase boundary. In contrast, the NiFeW matrix showed no nanostructural changes at 1273 K, likely due to cavity dissociation. Separate irradiations at 1273 K indicated that Ni2+ ions induced precipitate formation in the W phase, while He+ ions exclusively caused cavity formation. The microstructure of 87R DPT W irradiated at RT and subsequently annealed at 1273 K closely resembled that of material irradiated directly at 1273 K. Like oxide-dispersion-strengthened steels, the observed nanoparticle-embedded W can inhibit dislocation propagation, potentially delaying the ductile-to-brittle transition temperature. These findings highlight the potential of NiFeW nanoparticle-reinforced W composites as irradiation-resistant materials for fusion reactors.

  PublisherDOI

• Micro-pillar compression of proton-irradiated chromium examined using cross-sectional site selection, electron microscopy, and molecular dynamics simulation

  Journal of Nuclear Materials · 2024-07-18 · 3 citations

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  PublisherDOI

• Demonstration of Helide formation for fusion structural materials as natural lattice sinks for helium

  Acta Materialia · 2024-01-05 · 4 citations

  article
  PublisherDOI

• Sensing spin wave excitations by spin defects in few-layer-thick hexagonal boron nitride

  Science Advances · 2024-05-01 · 36 citations

  articleOpen access

  Optically active spin defects in wide bandgap semiconductors serve as a local sensor of multiple degrees of freedom in a variety of “hard” and “soft” condensed matter systems. Taking advantage of the recent progress on quantum sensing using van der Waals (vdW) quantum materials, here we report direct measurements of spin waves excited in magnetic insulator Y 3 Fe 5 O 12 (YIG) by boron vacancy <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mrow><mml:msubsup><mml:mi>V</mml:mi><mml:mi mathvariant="normal">B</mml:mi><mml:mo>−</mml:mo></mml:msubsup></mml:mrow></mml:math> spin defects contained in few-layer-thick hexagonal boron nitride nanoflakes. We show that the ferromagnetic resonance and parametric spin excitations can be effectively detected by <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mrow><mml:msubsup><mml:mi>V</mml:mi><mml:mi mathvariant="normal">B</mml:mi><mml:mo>−</mml:mo></mml:msubsup></mml:mrow></mml:math> spin defects under various experimental conditions through optically detected magnetic resonance measurements. The off-resonant dipole interaction between YIG magnons and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mrow><mml:msubsup><mml:mi>V</mml:mi><mml:mi mathvariant="normal">B</mml:mi><mml:mo>−</mml:mo></mml:msubsup></mml:mrow></mml:math> spin defects is mediated by multi-magnon scattering processes, which may find relevant applications in a range of emerging quantum sensing, computing, and metrology technologies. Our results also highlight the opportunities offered by quantum spin defects in layered two-dimensional vdW materials for investigating local spin dynamic behaviors in magnetic solid-state matters.

  PublisherOA PDFDOI

• Origin of Topological Hall‐Like Feature in Epitaxial SrRuO₃ Thin Films

  Advanced Electronic Materials · 2023-04-23 · 19 citations

  articleOpen access

  Abstract The discovery of topological Hall effect (THE) has important implications for next‐generation high‐density nonvolatile memories, energy‐efficient nanoelectronics, and spintronic devices. Both real‐space topological spin configurations and two anomalous Hall effects (AHE) with opposite polarity due to two magnetic phases have been proposed for THE‐like feature in SrRuO 3 (SRO) films. In this work, SRO thin films with and without THE‐like features are systematically Investigated to decipher the origin of the THE feature. Magnetic measurement reveals the coexistence of two magnetic phases of different coercivity ( H c ) in both the films, but the hump feature cannot be explained by the two channel AHE model based on these two magnetic phases. In fact, the AHE is mainly governed by the magnetic phase with higher H c . A diffusive Berry phase transition model is proposed to explain the THE feature. The coexistence of two Berry phases with opposite signs over a narrow temperature range in the high Hc magnetic phase can explain the THE like feature. Such a coexistence of two Berry phases is due to the strong local structural tilt and microstructure variation in the thinner films. This work provides an insight between structure/micro structure and THE like features in SRO epitaxial thin films.

  PublisherOA PDFDOI

• Microstructure and micromechanical responses of bulk nanostructured high entropy alloy after heavy-ion irradiation at 500°C

  Scripta Materialia · 2023-06-28 · 7 citations

  article
  PublisherDOI

• Enhanced radiation resistance of W-based HEA under helium-ion irradiation conditions

  Journal of Nuclear Materials · 2023-10-01 · 35 citations

  articleOpen access
  PublisherOA PDFDOI

Frequent coauthors

• Lin Shao

  32 shared

• Yongqiang Wang

  Los Alamos National Laboratory

  19 shared

• Yanwen Zhang

  17 shared

• William J. Weber

  Knoxville College

  14 shared

• Jonathan Gigax

  12 shared

• Tianyi Chen

  11 shared

• Y. Chen

  University of North Carolina at Charlotte

  10 shared

• Nan Li

  Air Force Medical University

  10 shared

Education

• Doctor, Nuclear Engineering

  Texas A&M University

  2014

Awards & honors

• Presidential Professor for Teaching Excellence Award conferr…
• Association of Former Students University-Level Distinguishe…