Contact:
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Yong Liu |
Arnaud Magrez |
Booking of the PPMS
The PPMS DynaCool uses a single two-stage Pulse Tube cooler to cool both the superconducting magnet and the temperature control system, providing a low vibration environment for sample measurements. The PPMS DynaCool offers continuous low temperature control, precise field and temperature sweep modes, as well as a built-in cryopump
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| PPMS Specifications |
Measurement Options
Electrical:
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DC Resistance:
DC transport for up to three channels on a standard puck can be measured using the DC Resistivity Option for the PPMS. Bridge channels can be individually configured for various levels of current excitation or power limitation, as well as enabling automated polarity-switch averaging to remove static DC offset voltages.
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The magnetoresistance (MR) of SrMnSb2 single crystals. The quantum oscillations were observed at low temperatures in (c). |
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AC Resistance (ETO):
The Electrical Transport Option (ETO) leverages a digital lock-in technique to measure resistance in a traditional Kelvin sensing (4-probe) configuration across a wide dynamic range; this is extended further by the special 2-probe high-impedance mode for a total range spanning nearly fifteen full decades. The two modes feature 8 MΩ of overlap so data can be normalized for a complete curve across both ranges. Additional functions like I-V curve profiling and differential resistance measurements extend the utility of the ETO to non-ohmic materials as well as device characterization and screening.
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The magnetic field dependence of transverse (Hall) resistivity ρxy at different temperatures in Ba0.08K0.92Fe2As2 single crystals. Temperature dependence of Hall coefficient RH. |
Vibrating Sample Magnetometer (VSM):
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DC magnetic susceptibility:
| Linear Transport Motor and Quartz sample holder and VSM coil set. |
The Vibrating Sample Magnetometer (VSM) option employs a puck-based first-order gradiometer coil set and high-resolution linear transport motor that enables the PPMS to operate as a sensitive magnetometer. The static (DC) magnetic moment of the sample can be measured as a function of temperature or field. With a typical 1 second averaging time per datum, data acquisition rates are comparatively fast. Furthermore, measurements as a function of sweeping the measurement temperature or field are possible. An included set of standard sample holders enable measurements of a wide variety of sample sizes and morphologies, such as: small single crystals, thin films (can be oriented with applied field in- or out-of film plane), sintered polycrystalline pieces, and loose powders.
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Vibrating Sample Magnetometer Specifications (for standard bore in zero field, unless indicated). *Parameters are integration-time dependent; stated values are for integration times of 1 second at 40 Hz, 2 mm amplitude excitation. Total observed noise is the sum of the floor and relative components. Specifications are subject to change without notice. |
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Temperature and magnetic field dependences of magnetization in both H⊥a axis and H||a axis configurations for SrMnSb2 crystals. |
- AC Susceptibilty (ACMS II):
The AC Measurement System (ACMS II) is a versatile susceptometer for magnetic measurements. In addition to a mutual induction-based determination of the AC susceptibility, the ACMS II enables the user to perform DC magnetization measurements without having to change sample mounts, electronics, or the hardware configuration. The coil set assembly can be used over the entire field and temperature range of the base system.
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The superconducting transition in a NbTiN thin film. |
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Heat capacity option:
The Heat Capacity Option leverages a puck-based microcalorimeter design capable of measuring sample heat capacity across the full range of temperature and field afforded by the PPMS. Operating in high vacuum, a sample is subjected to a thermal pulse and its temperature response is recorded as in a traditional semi-adiabatic relaxation technique. Fitting algorithms based on a model of the thermal circuit extract sample heat capacity from this curve. Typical measurements collect heat capacity as a function of temperature; measurements under a constant field are possible after using the automated field calibration function of the software.
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Temperature dependence of the specific heat of TbPO4 single crystal. |
Thermal Measurements:
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Thermal Transport (TTO):
Using the Thermal Transport Option (TTO) all three constituent experimental parameters of the thermoelectric figure of merit (ZT) can be measured simultaneously and continuously as a function of temperature. Operating in high vacuum, a sample is subjected to a thermal pulse and its temperature and voltage responses are recorded. Fitting algorithms based on a model of the thermal circuit extract a sample’s thermal conductance and thermopower from these curves, and a resistance measurement is executed immediately after. ZT is automatically calculated as well, and can be evaluated across the full range of temperature and field afforded by the PPMS.
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A comparison of thermal conductivity data collected with different modes: (1) continuous measurement; (2) single measurement stability; (3) single measurement timed |