Technical Specifications for Physical and Magnetic Property Measurement System
[PMPMS] to be purchased at NIIST, Trivandrum
Our interest is to study novel rare-earth based magnetic materials and superconductors (both
intermetallics and oxides) for the application as magnetic refrigeration and permanent magnets and
superconducting leads. In order to study these materials we require the following physical property
characterizations in the variable temperature and magnetic fields up to 9Tesla using cryogen free magnet.
0. DC Magnetization (Vibrating Sample Magnetometer) (temperature range from 2K to 1000K
continuous operation).
1. Electro-transport measurements (Temperature Range 2 to 400 K)
2. Specific Heat capacity (Temperature Range 2 to 390 K)
3. Option for having Multifunctional probe for the attachment of additional physical property
measurements.
Provision for following additional measurement options to be added to the basic system in future must be
available.
0.
1.
2.
3.
AC Susceptometer for measuring AC magnetization.
Flexibility to extend the temperature range to milli Kelvin range using He 3.
Thermal conductivity probe for measuring the thermal conductance.
Possibility of MFM attachments
Specifications for cryogen free measurement platform
No need to have liquid He for first starting and later restarts after maintenance.
Two stage pulse tube cooler required to cool both the superconducting magnet and the temperature
control system.
Maximum field: up to 9T with highly stable bipolar power supply with overvoltage protection.
Central field uniformity for VSM ± 0.01% over 3 cm axial length.
System must have
1. ≤24 hours or time to cool down the magnet for initial starting
2. ≤ 45 minutes to cool down sample from high temperature to 1.9 K
3. ≤7 minutes to full field
4. Temperature range 1.8K to 400 K (continuous low temperature control and sweep mode for
indefinite period and smooth transition through 4.2K)
5. Built in magnetic shield for better laboratory space utilization
6. Built in Cryopump to pump sample chamber to 10-4 torr in ten minutes
(These parameters have to be demonstrated by the companies at one of their installations in India
in case of any doubt)
Specifications for VSM:
1.
2.
3.
4.
5.
6.
Longitudinal configuration, Central field uniformity for VSM ± 0.01% over 3 cm axial length
Sensitivity ≤2x10-6 emu/tesla with 1 second averaging
Relative noise level should be 6x10-7emu/Hz or less is preferred (to be specified by the company).
Accuracy 0.5% or better in 2.8mm diameter x 4mm is preferred.
Wide range of oscillation frequency is preferred (0 to 40Hz) (to be specified by the company).
The temperature range from 2K to 1000K should be in continuous operation with minimum
number of stages (2-400 K and 300-1000 K ).
7. Suitable sample holders to be provided to keep samples in the form of powders, pellets and thin
films.
Specifications for Specific heat attachment
1. Measured temperature Range should be as large as possible, preferably in the range of 2–390 K
(their range to be specified by the company)
2. Sample Size: 1–500 mg (20 mg, typ.)
3. Vacuum at sample space 10-4 torr or better.
4. Heat Capacity Resolution: 10 nJ/K at 2 K (to be specified by the company and the claim to be
corroborated by the appropriate references of the papers/patents published by the scientists using
their equipment)
5. Typical measurement Accuracy: < 5%, 2–300 K,< 2% typical
6. Suitable sample holders to be provided to keep the sample along the field directions, in order to
protect the strongly magnetic samples while the sweeping the magnetic field.
Specifications for Electro-transport:
The scientific techniques for the electro-transport measurements are very important, thus the company
must be specified their scientific techniques.
1. Hence, the provision to measure the AC and DC resistance must be of four-probe configuration
techniques and for the Hall-effect technique must be using the 5-probes or 6-probes
configuration.
General specifications:
1. Data acquisition system must be the latest version based on CAN architecture. (Company must
specify their data acquisition system).
2. It is highly desirable that the instruments required for the above mentioned property
measurements shall be from the same manufacturer in order to maintain the compatibility of the
magnet and cooling systems and to maintain the speed and accuracy. (Company must specify
manufactures of the different instruments coupled to the magnet). This point is also important in
the event of a breakdown in future.
3. He3 option to go down to 400 mK (single shot), <0.5K (continuous mode)
4. Any other attachments needed for the working of PMPMS like chillers, compressors etc. which
needs to be procured locally has to be quoted along with the machine and supplied along with the
machine.
5. The capacity, rating and type of the uninterrupted power supply [UPS] may be specified along
with the list of suppliers.