Magnet, Low Temperature, and Optical Facility

Technological Institute, FB24
TEL: (847) 491-4212

Facility Director: John B. Ketterson, Physics & Astronomy Department
Facility Technician: Oleksandr Chernyashevskyy
Facility Committee Members: John B. Ketterson, Robert Chang, Nathaniel Stern

This facility maintains various magnet, cryogenic and optical systems operating either separately or together. The systems are designed to be as flexible as possible, and to allow several types of measurements to be performed over a wide range in magnetic field, temperature, and probe frequencies (including both uhf/microwave and optical). The dc and uhf/microwave frequency measurements that are routinely performed include magnetization and magnetic susceptibility, acoustic propagation, microwave absorption, electrical transport (including thermoelectric measurements). Routine optical measurements include optical absorption, photoluminescence, pump-probe studies, and Raman spectroscopy.

Our equipment includes cryostats, magnets, magnetometers, a nanovoltmeter, constant-current sources, and constant-voltage sources. The magnetometers include a computer-controlled Quantum Design Magnetometer (MPMS5) that permits SQUID magnetic-moment sensitivity (and a user probe for transport measurements), a LAKESHORE AC susceptometer for measuring both real and imaginary components of susceptibility, and a quick-turnaround AC bridge susceptometer. The MPMS provides the exceptional sensitivity of a SQUID-based magnetometer in a fully automated, analytical instrument. It provides a much needed solution for a unique class of magnetic measurements, meeting the needs of research in key areas such as high-temperature superconductivity, biochemistry, and magnetic recording media. This system was upgraded in 2004 by the addition of a horizontal rotator option and an “oven” insert for high-temperature measurements. This instrument can measure DC magnetic susceptibility and magnetic moments on samples as small as a few mg.

Field range: -5.0 T to 5.0 T Temperature range: 1.8 K to 700 K Measurement range: 10 -7 to 100 emu Absolute sensitivity: 10 -7 emu Additional cryostats include a computer-controlled Quantum Design Physical Properties Measurement System (PPMS) and a SHE VTS 50 SQUID susceptometer outfitted for low-noise transport measurements. The PPMS was designed to measure heat capacity, thermal transport, and thermoelectric effects. Key optional features of the MPMS have been greatly expanded and improved in the PPMS. The PPMS brings a new level of measurement automation to researchers in rapidly expanding fields such as materials science, condensed matter physics, biology and analytical chemistry. The tremendous flexibility of the PPMS – open architecture – lets you create your own experiments and easily interface your own third-party instruments to the PPMS hardware. For example, we can connect a user’s equipment to PPMS analog outputs with signals proportional to magnetic field, system temperature, bridge resistance, bridge excitation, etc.
Field range: -9.0 T to 9.0 T
Temperature range: 1.9 K to 390 K
Thermal conductance accuracy: 5%
Heat capacity sample size: 1 to 200 mg
Heat capacity resolution: 10nj/K at 2 K

Additional Optical Resources:
Andor 303 mm focal length Czerny-Turner spectrograph and DU420A-BEX2-DD
thermoelectric cooled camera.
EKSPLA PL2143SS 30 picosecond pulsed neodymium-doped yttrium aluminum
garnet (ND:YAG) 1064 nm laser with doubler (532 nm), trippler (355 nm),
and OPA. 10 Hz repetition rate for 30 mJ pulses Spectra-Physics
Millennia V 532 nm 5 Watt solid state neodymium yttrium vanadate laser
Kimmon Koha IK5451R-E Helium Cadmium Laser. 16 mW at 325 nm or 77.4 mW
at 442 nm. LHe optical cryostat

Data Acquisition Capability*: We designed and made new low capacity probe for Quantum Desighn PPMS. It has 10 times lower background/residual capacity than standard company recommended PPMS set-up. It is great for study of dielectric properties of various materials including organic and biological.

*Probe was designed and made upon request of users from Dr. Stoddart and Dr Stupp
research group.

Ease Of Use The hallmarks of our instruments are automation and ease of use. We can quickly and easily configure them to perform different types of measurements. In a matter of minutes we can install a measurement application, set up an automated sequence, and start collecting meaningful data. And, our equipment is designed to run 24 hours a day, 7 days a week. We know your time is valuable, so we have laboratory automation on a new level. While the PPMS or MPMS runs your measurements, you can be analyzing data from previous measurements, planning your next experiment, and creating new materials. The MPMS and PPMS work like dedicated systems, but their tremendous flexibility lets you perform different types of measurements. Plus, we can easily integrate a user’s unique experiment with our measurement systems. Samples can be easily prepared from a variety of materials. The exceptional dynamic range of our devices allows us to accommodate samples in many forms, from single crystals to bulk solids, films and powders.

Recent Patents:
United States Patent #7,977,668
Date: July 12, 2011
Inventors: I. Nevirkovets, J. Ketterson, O. Chernyashevskyy, S. Shafraniuk
Title: Multilayer structure with zirconium-oxide tunnel barriers and applications of same
Abstract: A multilayer structure with zirconium-oxide tunnel barriers. In one embodiment, the
multilayer structure includes a first niobium (Nb) layer, a second niobium (Nb)
layer, and a plurality of zirconium-oxide tunnel barriers sandwiched between the
first niobium (Nb) layer and the second niobium (Nb) layer, wherein the plurality of
zirconium-oxide tunnel barriers is formed with N layers of zirconium-oxide, N being
an integer greater than 1, and M layers of zirconium, M being an integer no less
than N, such that between any two neighboring layers of zirconium-oxide, a layer of
zirconium is sandwiched there between.