Synthesis

Solid-State Synthesis

Nearly all discoveries in materials research start with the synthesis of novel compounds. UT-IAMM houses one of the largest solid-state synthesis laboratories in the nation with a wide variety of furnaces for the synthesis of polycrystalline materials and large single crystals. Our motto: those who control the synthesis direct the future of materials science.

Thin Film Growth

Epitaxial Synthesis

Molecular beam epitaxy is the most advanced thin film synthesis technique for the growth of single-crystalline thin films with the highest purity and atomically precise control of the thickness and composition. The quantum materials group employs molecular beam epitaxy synthesis of transition metal oxides and chalcogenides as well as conventional group III-V semiconductors. It also employs pulsed laser deposition, or “laser molecular beam epitaxy,” of complex oxide materials that are very difficult to grow via thermal molecular beam epitaxy. The oxide molecular beam epitaxy apparatus is an IAMM core facility.

High-Throughput Screening

Combinatorial Thin Film Sputtering

Combinatorial thin film sputtering is a versatile technique that allows for high-throughput screening for rapid materials discovery. The team leverages combinatorial thin films to survey very large phase spaces for both compositionally complex alloys and ceramics, including oxides, nitrides, and carbides. The system is comprised of four sputtering sources that can be deposited simultaneously at elevated temperature and with substrate bias. A sputtering model has also been developed so optimum sputtering parameters can be arrived at quickly to cover the desired composition space.

High-Temperature Processing

High Temperature Formation and Processing (UT)

High temperature furnaces

High-quality high-temperature furnaces can reach temperatures up to about 1700°C. Available furnaces are easy to use and have programmable controllers that allow for precise temperature and process control, resulting in high-temperature heating with excellent conformity and consistency.

Uniaxial hot press

The uniaxial hot press, up to 2000°C and 25 tons, is used for high-temperature and high-pressure consolidation of materials such as metals, ceramics, and composites. It supports uniform density, reduced porosity, enhanced mechanical properties, and improved structural integrity for applications under extreme environment conditions.

Spark Plasma Sintering

Spark Plasma Sintering is a powder metallurgy technique used for consolidation and densification of metals, ceramics, and composites from powders. It applies pressure and pulsed direct current to the powder compact simultaneously, enabling rapid consolidation at lower temperatures and shorter processing times than conventional sintering methods.

ORNL Processing

High Temperature Formation and Processing (ORNL)

ORNL capabilities include levitation devices for container-less laser heating and quenching at 2500°C and above, atmosphere-controlled off-line physical property measurements, and in situ scattering studies.

• Aerodynamic levitation for oxides up to 3000°C with rapid laser heating and cooling using Ar and Ar/O₂ mixtures.
• Electrostatic levitation for metals up to 3000°C under high vacuum.
• Measurements related to melting points, phase transitions, thermal expansion, density, viscosity, surface tension, resistivity, crystallization velocity, and vapor pressure.

Electronic Structure

Electron Spectroscopy

The electronic properties of quantum materials are studied with electron spectroscopies such as X-ray photoelectron spectroscopy, Auger electron spectroscopy, angle-resolved photoemission with time-resolution capability, and high-resolution electron energy loss spectroscopy in reflection mode. These techniques provide direct information on electronic structure and excitations in quantum materials. The photoelectron spectrometers are part of an ultrahigh vacuum suite with added capabilities for molecular beam epitaxy and scanning tunneling microscopy.

Scanning Tunneling Microscopy / Surface Imaging

Topographic and Spectroscopic Surface Imaging

Scanning tunneling microscopy is a powerful tool for studying the topography of a crystal surface or thin film with atomic resolution. It measures a small quantum mechanical tunneling current between an atomically sharp metal tip and the crystal surface as a function of tip location. Scanning tunneling microscopy is also a spectroscopic tool that can measure the local electronic density of states as a function of applied bias and tip location. Differential conductance maps provide key information about the Fermi surface, topological edge states, or superconducting order-parameter symmetry.

Microscopy Core

Electron Microscopy

IAMM’s Microscopy Core Facility houses a variety of scanning probe and electron microscopes, including an atomic force microscope, a nano-indenter, two transmission electron microscopes, a scanning electron microscope, and two Dual Beam Focused Ion Beam instruments. One showcase instrument is the 300 keV ThermoFisher monochromated and aberration-corrected transmission electron microscope / scanning transmission electron microscope with spatial resolution down to 40 pm, allowing atomic-resolution energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy. Another is a Plasma Focused Ion Beam providing ion beams of Xe, Ar, N, and O for imaging and processing of prototypical devices, with energy-dispersive X-ray spectroscopy and electron backscatter diffraction for microstructural and chemical analysis.

X-ray Diffraction

Structural Characterization

Characterization of new materials usually starts with structure determination through X-ray diffraction. IAMM’s Diffraction Core Facility houses a variety of X-ray diffractometers. Basic usage includes identification and quantification of crystalline phases, space group symmetry and lattice parameters, crystallite size, and micro strain. More advanced uses include high-temperature in situ experiments, preferred orientation with pole figures, residual stress determination, and thin-film studies with X-ray reflectivity.

Mechanical Testing

Multi-scale Mechanical-Property Characterization

This capability offers nanoindentation-based structure-property relationship characterization. Nanoindentation determines mechanical properties such as hardness and modulus at different length scales. A Nanoflip system is available for in-scanning electron microscope operation, allowing combined indentation and imaging. The iMicro can perform large numbers of automated indents in varying modes. The LECO machine maps hardness of large samples with automated imaging for rapid data analysis. Laser and optical tabletop microscopes characterize surface roughness and indentation profiles. Thermomechanical characterization tools also exist from meso to macro scale, including high-temperature differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, and bulk servohydraulic testing systems with environmental chambers for axial and multi-axial loading.

Physical Properties

Electrical and Magnetic Property Measurement

Quantum materials exhibit a wealth of electrical and magnetic properties. These can be measured using Quantum Design Physical Properties Measurement Systems and the MPMS-VSM magnetometer system. Researchers routinely access temperatures as low as 2 Kelvin and magnetic fields up to 14 Tesla. The magnetometer is equipped with a Helium-3 option for magnetization measurements down to 0.4 Kelvin.

Cryogenics

Research at Low Temperatures

Many experiments are done at low temperatures and require liquid helium cooling, which is an increasingly rare and expensive commodity. To reduce the cost of low-temperature experiments, researchers have access to a central helium recovery and liquefaction facility capable of producing 60 liters of liquid helium per day. The system is equipped with a 500-liter storage dewar.

Radiation Effects

Ion Beam Materials Laboratory

The Tennessee Ion Beam Materials Laboratory is a UTK core user facility available locally to the University of Tennessee community and to domestic or international collaborative research institutes. The laboratory is equipped with a 3 MV tandem accelerator, a 30 kV electron gun, two ion sources, three beamlines, and four end stations. These provide capabilities for ion beam analysis, ion beam materials modification, fundamental research on ion-solid interactions, and applied research on radiation effects in materials for terrestrial and space radiation applications. Upcoming milestones include a new 200 kV scanning transmission electron microscope, a 300 kV ion implanter, a dedicated low-energy beamline, and two new low-energy ion sources.

Tennessee Ion Beam Materials Laboratory website

High Pressure

Diamond Anvil Cells

Static high-pressure experiments can be performed using diamond anvil cells. Pressures of up to a few hundred GPa can be reached. Conventional, rotational, and dynamic diamond anvil cells can be used to study how shear and fast compression or decompression affect material response. High temperatures can be simultaneously coupled with pressure experiments using resistive or laser heating, reaching a few hundred to several thousand Kelvin. Diamond anvil cells can be used for in situ measurements of equations of state, melting curves, and phase transformation kinetics under controlled extreme conditions. They can also be used to synthesize materials far from equilibrium with novel properties and improved durability.

ORNL Neutron Sources

Neutron Scattering

Neutron scattering is a powerful way to probe magnetism and quantum behavior in materials. CAMM researchers principally use the Spallation Neutron Source and High Flux Isotope Reactor, two of the world’s premier neutron facilities located at Oak Ridge National Laboratory. Researchers undertake experiments on the structure and dynamics of materials and develop new techniques and sample environments. Much of the work uses the Shull Wollan Center, the UT Center for neutron science on the ORNL campus.

Computing

High-Performance Computing

The Infrastructure for Scientific Applications and Advanced Computing at UT offers secure and non-secure enclaves containing thousands of advanced computer cores and multi-GPU nodes integrated with a high-speed Lustre file system with petabyte-scale storage capacity. The Infrastructure for Scientific Applications and Advanced Computing is connected to the larger U.S. academic internet through Internet2 connectivity. CAMM researchers also use Oak Ridge Leadership Computing Facility supercomputing resources at ORNL, including the exascale Frontier supercomputer and other national facilities.