Absolute temperature measurement (T < 100 mK region) from anisotropy of gamma radiations emitted from oriented⁶⁰Co nuclei in a single crystal of hcp cobalt is found to depend on the shape of the crystal. This dependence is attributed to some closure magnetic domains not oriented along thec-axis of the disc shaped crystal studied. A long rectangular strip of cobalt crystal is found to give correct angular distribution ofγ-radiations and, therefore, suitable for thermometry.

The design and fabrication of an all-metal cryostat, superconducting magnet and variable temperature sample holder insert for the measurement of magnetoresistance at temperatures in the range 1.5–300 K are described. A field of 50 kilogauss has been achieved at the centre of a one-inch bore superconducting solenoid and has a uniformity of 0.2% over an axial distance of 20 mm around the centre of the solenoid. Also, the design and construction of vapour cooled current leads for the magnet are discussed.

The design of a simple and inexpensive³He insert for the existing ac susceptometer is described. The system uses a home built mutual inductance bridge for the ac susceptibility measurements from 0·4 K to 300 K. Simple and inexpensive design with the top loading facility are the main features of this set up. The insert can also be used as a continuously³He operating refrigerator down to 0·5 K.

We describe a simple, low cost pc based card for the measurement of heat capacity using adiabatic calorimetry at low temperatures. This card provides the control pulse to the sample heater as well as trigger pulse to the nano-voltmeter which monitors the sensor voltage (Ge sensor, Lake Shore Inc., USA). We have also added a 12 bit DAC on this card and this is used for remote setting of the heater current of an old SHE (now Biomagnetic, Inc., USA, model CCS) analog constant current source. Although this card is used here for heat-capacity measurements, the same can also be used for thermo-power and thermal-conductivity measurements.