Shared Facilities

FUNCTION:
This facility maintains various magnet and cryogenic 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 frequency. The types of measurements that are routinely performed include magnetization and magnetic susceptibility, acoustic propagation, microwave absorption, and electrical transport (including thermoelectric measurements).

EQUIPMENT:
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.