VersaLab™
3 Tesla, Cryogen-Free Physical Property Measurement System

Electrical transport measurements like resistance, Hall effect and current-voltage spectroscopy are probes of electron interactions in solids. Scientists use these tools to detect phase changes such as superconductivity, magnetic ordering, or metal-insulator transitions. Electrical transport can also quantify the concentration and mobility of charge carriers or probe the bandgaps in semiconductors and superconductors.

• For performing AC Resistance, Hall Effect, I-V, and Differential Resistance (dV/dI vs. I) measurements.
• 1nV sensitivity, 10 nΩ resolution at 100 mA
• AC and DC drive amplitude 10 nA to 100 mA
• Resistance ranges from 10 µΩ to 5 GΩ

In thermal transport, a temperature gradient is induced in a material to measure its thermal conductivity as well as the thermoelectric effect to determine the Seebeck coefficient. These are important transport quantities for similar reasons as listed for electrical transport, as well as being essential in characterizing materials used in thermoelectric power generation and refrigeration.

AC Resistivity ρ

• Measured by using precision DSP current source and phase-sensitive voltage detection.

Thermal Conductivity κ

• Measured by applying heat from the heater shoe in order to create a user-specified temperature differential between the two thermometer shoes.

Seebeck Coefficient α

• Measured by creating a specified temperature drop between the two thermometer shoes - just as it does to measure thermal conductivity. However, for Seebeck coefficient the voltage drop created between the thermometer shoes is also monitored.

Thermoelectric Figure of Merit ZT

• Determined here simply as the algebraic combination α²T /(κρ) of the three measured quantities - thermal conductivity, Seebeck coefficient, and AC electrical resistivity.

Heat capacity measurements probe the ability of a sample to absorb heat – it quantifies the material's specific heat and entropy which are fundamental thermodynamic quantities. Entropic effects in solids that can be probed with heat capacity include the magnetocaloric effect and phase transitions such as metal-insulator, superconductivity, or magnetic ordering.

• Completely automated relaxation technique from 50 - 400 K
• Integrated data acquisition electronics and analysis software

Vibrating Sample Magnetometry is a fast and sensitive technique to determine a sample's magnetic dipole moment. The moment arises from the material's magnetization density which is a fundamental thermodynamic quantity. This tool can be used to study phenomena such as superconductivity, ferromagnetism, superparamagnetism and magnetic frustration.

• RMS Sensitivity: < 10^-6 emu with 1 sec averaging
• Optional VSM Oven up to 1000 K

Torque magnetometry probes the magnetic anisotropy of a small sample and gives a unique insight into the microscopic arrangement of magnetic spins. This technique is widely used in the development of magnetic recording media.

• Measures the magnetic torque = mBsinθ
• Designed to measure moments of very small anisotropic samples
• Moment Sensitivity: 3 x 10^-7 emu at 3T