About Instrument and its applications-
Low temperature and high magnetic field facility for Physical Properties Measurment establish at IIC, IIT Roorkee in the year 2019. The facility is single characterization unit to measure electrical, thermal, and magnetic properties from 400 K till 1.8 K in presence and absence of high magnetic field (~12T). This system is a modular system having a cryostat and cryomagnet for temperature variation and magnetic field, respectively. Different modules of measurements can be exchanged as per the requirement and system can be configured easily for various measurements. The system does not require liquid cryogen (liquid He) and close cycle system can be used to attain the low temperature control and to conduction cool with free superconducting magnet. Helium gas requirement has reduced considerably due to pulsed tube technology. Following measurements can be performed regularly using the facility:
1) Electrical transport characteristics: Four probe resistivity (DC and AC) measurements, current-voltage measurements, magnetoresistance measurements.
2) Thermal transport: Thermal conductivity, Seebeck coefficient, thermoelectric figure of merit
3) Heat Capacity
4) Magnetic characteristics: DC and AC magnetization

Applications:
The application areas of AAS are very wide including environmental analysis, medicines, metal alloys etc.

General Information-
Make- Quantum Design
Model- DynaCool PPMS
Year of Installation- 2019

Specifications-

1) No need for liquid cryogens
2) Temperature range: 1.8 K – 400 K
3) Magnetic field: ±12 T
4) Solid sample
5) Built-in Cryopump for high vacuum applications (<10-4 Torr)

Measurements-

1) Heat Capacity
Specifications-
a) Temperature range: 1.8 K to 400 K
b) Sample requirement: 1-500 mg (20 mg, typical), solid
c) Resolution of measurement: 10 nJ/K @ 2 K
d) Accuracy of measurement: < 5% over 2 K- 300 K (< 2% typical)

Sample Requirements-
Solid sample: 1 mm x 2 mm x 2 mm pellet or thin film form

2) Thermal Transport

(a) Specifications of Thermal conductance-
i) 1-25 mW/K for high T = 400 K
ii) 100 µW/K - 100 mW/K for intermediate T = 50 K
iii) 10 µW/K - 1 mW/K for low T = 1.9 K
(b) Specifications of Seebeck coefficient-
i) Accuracy of measurement (approximate range): 1 µV/K - 1 V/K

Sample Requirements-
Solid sample:
a) 2 mm x 2 mm x 9 mm Brick shape
b) 2 mm x 6 mm Disk shape

3) Electrical Transport

Specifications-
a) Measurement of AC resistance, I-V and differential resistance (dV/dI vs. I) measurements etc.
b) Sample size: max. 10 x 10 mm2
c) 1 nV sensitivity, 10 nΩ resolution at 100 mA
d) AC and DC drive amplitude: 10 nA to 100 mA

Sample Requirements-
Solid sample: 1 mm x 3 mm x 3 mm or 2 mm x 4mm x 4mm or 2 mm x 5mm x 5mm pellet or thin film form

4) Vibration Sample Magnetometer (DC magnetization measurements)

Specifications:
a) Temperature range: 1.8 K to 350 K
b) Coil type: 1st Order Gradiometer, Cu
c) Coil set bore: 6.3 mm
d) Oscillation frequency (calibrated): 40 Hz
e) Oscillation amplitude (typical): 2mm peak
f) Sample mass: < 1 gm, solid/thin film: < 4 x 5X1 mm3
g) Data rate and averaging window (typical): 1 sec
h) RMS sensitivity at zero field: Larger of 6 x < 10-7 emu or 0.5%
i) RMS sensitivity at field B: Larger of [6 x < 10-7 emu + 3 x 10-7 emu/tesla x B(T)] or 0.5%

Sample Requirements-
1) Powder sample: 5 mg to 20 mg
2) Solid sample:
a) 2 mm x 2 mm x 2 mm pellet or thin film form (Perpendicular)
b) 1 mm x 3 mm x 3 mm or 1 mm x 3mm x 4mm or 1 mm x 4mm x 5mm pellet or thin film form (Parallel)

Note: A Large bore coil of 12 mm diameter is available but sensitivity is one order of magnitude lower in comparison to small bore coil.

5) AC susceptibility

Specifications-
a) Temperature range: 1.9 K to 350 K
b) AC frequency range: 10 Hz to 10 KHz
c) AC drive amplitude range: 5 mOe to 15 Oe
d) Sensitivity range: 1 x 10-8 emu @ 10 kHz
e) DC magnetization measurement sensitivity: 5 x 10-6 emu
f) DC magnetization accuracy: 1%

Sample Requirements-
1) Powder sample: 15 mg to 20 mg
2) Solid sample:
a) 2 mm x 2 mm x 2 mm pellet or thin film form (Perpendicular)
b) 1 mm x 3 mm x 3 mm or 1 mm x 3 mm x 4 mm pellet or thin film form (Parallel)

Note: High pressure option is available. User should contact to Prof. Vivek K. Malik prior booking an appointment for the same.


Contact Person-
Dr. Vipin Chawla
Technical Officer - III
E-mail: vipin.mic@iitr.ac.in
Tel: +91-1332-284580