Resistivity Measurement System
Introduction
The RnX series measurement systems provide a versatile platform for a wide range of studies into the properties of materials as a function of temperature, time and magnetic field. As standard, these include DC and AC resistivity, magnetisation and susceptibility.
The standard RnX series enable
measurement of sample resistance in the range of 106 to 10-6 Ohms in a temperature range of 1.6 to 300K. If measurements are required in a magnetic field Cryogenic offers a range of magnets suitable for every need providing up to 14T along the sample access and 8T orthogonal to the sample access.
Resistance measurements are made using a 4 terminal probe with drive currents from 1A up to 100mA. The sensitivity of the data acquisition system is 0.1 V to 1000mV full scale. In order to verify each measurement, the system simultaneously measures both the 2 and 4-terminal voltages over the sample. The applied voltage is dynamically reversed in order to subtract thermal potentials, and the measurement averaged.
Optional Features
High temperature oven insert
An extension of the standard temperature range to high temperature is available using the oven insert. In normal operation, the system has a continuous temperature range of 1.8 to 300K. With the oven insert this is complemented by allowing measurements in the range 200- 700K.
Very low field option
The addition of a precision 4-quadrant low current source (250mA o/p) to the main power supply, enabling precise low field excursions on the sample. The low field range is dependent upon the maximum field of the main magnet.
Low resistance and critical
current measurement
For measurement of very low resistance materials we include the facility to measure down the nano-Ohm resistances. This facility includes a precision nanovolt amplifier and 1A current source.
Critical current measurement
to 120A sample current
A probe for critical current measurements to 120A for use with high conductivity or superconducting materials. Voltage measurement to 0.1 Volt or better is offered.
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