Research Facilities
Our research is multi-faceted and requires expertise in experiment design, sample fabrication, magnetic characterization, and computational simulations. What follows is an overview of all the tools our students will be trained on. These tools are widely used by both private and public institutions across various technology sectors, including:
- Research & Development: IBM Research and National Labs such as Argonne, Los Alamos, Sandia, Berkeley, Oak RIdge, Brookhaven, and Fermilab
- Semiconductors: Intel, Samsung Electronics and Micron
- Data Storage: Seagate, Western Digital and NVIDIA
- Aerospace Surface Engineering: Hardide Coatings, Honeywell and Boeing
- Solar Energy: First Solar and Trina Solar
- Biomedical Coatings: Medtronic and Boston Scientific
- Batteries: Solid Power, Panasonic and Quantumscape
- MEMS Systems: Bosch Sensortec, STMicroelectronics and Microchip Technology
- Display Technology: LG Displays and Samsung Displays
Nanofabrication
Magnetron Sputter Deposition
Magnetron sputter deposition (or just 'sputtering') is a widely used thin-film deposition technique that enables the controlled coating of materials onto a substrate with atomic precision. It works by creating a plasma in a vacuum chamber, where ions from an inert gas (typically argon) are accelerated towards a target material. When these ions collide with the target, atoms are ejected and then deposited onto a substrate, forming a thin film. Magnetrons, which are magnets placed behind the target, increase the efficiency of the sputtering process by trapping electrons near the target to sustain a stable plasma. Sputtering is highly versatile, offering uniform coatings, high deposition rates, and excellent control over film thickness and composition, making it essential in fields like electronics, optics, and materials science.
Our students are trained on how to use an AJA ATC 1800-F sputtering system to fabricate samples. The AJA has 5 sputtering sources, 1 DC and 1 RF power supply, and a base pressure < 50 nTorr.
Electron Beam Evaporation
Our students are also trained on how to use a Denton Explorer 14 E-beam Evaporator to fabricate samples. The Denton EBE system has 6 material pockets, a quartz crystal monitor, and a base pressure < 10 nTorr.
Electron-Beam Lithography
E-beam lithography (EBL) is a high-resolution technique used to create extremely fine patterns on a substrate by directly writing with a focused electron beam. Unlike traditional photolithography, which uses light and masks, EBL achieves nanometer-scale precision by scanning an electron beam over a resist-coated substrate in a pattern defined by a computer. The electron beam modifies the resist, which can then be developed to reveal nanoscale features that serve as templates for subsequent processing steps, such as etching or material deposition. EBL is crucial for research and development in nanoelectronics, photonics, and quantum devices, where precise patterning at sub-10 nanometer scales is required.
Photolithography
Photolithography is a key microfabrication technique used to pattern precise structures onto a substrate by using light to transfer geometric shapes from a mask onto a light-sensitive resist layer. In this process, a substrate coated with a photosensitive resist is exposed to ultraviolet (UV) light through a mask containing the desired pattern. The exposed areas of the resist undergo chemical changes, allowing selective removal in a subsequent development step, which reveals the pattern on the substrate. Widely used in semiconductor manufacturing, photolithography enables the creation of intricate circuits and microstructures essential for electronics, MEMS, and nanotechnology applications.
Magnetic Characterization
A key aspect of our lab is magnetic characterization, which assess both the static, quasi-static, and dynamic magnetization properties of a material or metamaterial. What follows is an overview of our magnetic characterization tools.
Magneto Optical Kerr Effect Microscopy
The Magneto-Optical Kerr Effect (MOKE) microscope is a powerful tool used to visualize and analyze magnetic domains and their behavior in thin films and surfaces. This technique leverages the Kerr effect, where polarized light undergoes a change in reflection angle and polarization state when it interacts with magnetized materials. In practice, a polarized light source is directed at the sample, and the resulting polarization changes in the reflected light—proportional to the sample's magnetization—are analyzed. This provides real-time imaging of magnetic domain structures and magnetization dynamics at micro- or nanoscale resolution. MOKE is a non-destructive technique that allows real-time visualization of magnetic domains, phase transitions, and magnetic dynamics under applied fields, making it invaluable in fields like spintronics, magnonics, and magnetic metamaterials research.
Our students are trained on how to use a Durham Magneto Optics (DMO)
NanoMOKE3 wafer mapper. The MOKE system is sensitive to Longitudinal, Transverse and Polar Kerr rotation and ellipticity, and is able to map out magnetic behavior of ultra thin samples in magnetic fields up to 0.75 Tesla.
Ferromagnetic Resonance Spectroscopy
Ferromagnetic resonance (FMR) spectroscopy is a technique used to study the magnetic properties and dynamic behavior of ferromagnetic materials by measuring their response to an applied oscillating magnetic field. In FMR, a sample is placed in a steady magnetic field, and a microwave frequency magnetic field is applied perpendicular to it. When the microwave frequency matches the natural precession frequency of the sample’s magnetization, resonance occurs, allowing detailed analysis of properties like magnetic anisotropy, damping, and g-factor. FMR spectroscopy is essential in fields such as magnonics, spintronics, and material characterization, providing insights into fundamental magnetic interactions and relaxation processes.
Micro-focused Brillouin Light Scattering
Micro-focused Brillouin Light Scattering (also known as µ-BLS) is a powerful technique for analyzing the mechanical and magnetic properties of materials on microscopic scales. By focusing a laser beam onto a small region of a sample, µ-BLS detects shifts in the frequency of scattered light caused by interactions with phonons (acoustic vibrations) or magnons (spin waves) within the material. These frequency shifts provide insights into properties such as elasticity, stiffness, and magnetic dynamics with high spatial resolution. µ-BLS is especially useful in fields like magnonics, materials science, and thin-film analysis, where localized information about acoustic and spin wave behavior is critical for understanding material performance.
Shared Characterization Tools
Physical Properties Measurement System
Vibrating Sample Magnetometry
X-Ray Diffraction and Reflectivity
Scanning Electron Microscopy
Atomic Force Microscopy
Magnetic Force Microscopy
Computational Simulation
We complement our experimental work with micromagnetic simulations run on Oklahoma State University's High Performance Computer Center (HPCC), using either the PETE Supercomputer or the TIGER Research Cloud. We use two well-known software packages: MuMax3 and OOMMF. MuMax3 was developed in 2014 by the excellent Dynamics of Functional Nano Materials (DyNaMat) Group at Ghent University, Belgium, to leverage GPUs to accelerate computation speed and allow for more complex simulations. Our students learn how to code MuMax3 simulations in Go, submit jobs to the GPUs on PETE, and process the data using Python in Jupyter Notebooks. OOMMF was developed in 1999 by Mike Donahue and Don Porter at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland. OOMMF supports micromagnetic simulations on multiple CPU, and comes with a fully integrated visualization suite. Our students learn how to code OOMMF simulations in Tcl/Tk, submit jobs to TIGER, and process the data using Python in Jupyter Notebooks.