Thermal Expansion And Magnetostriction Measurements Using A Quantum Design Physical Property Measurement System

Capacitive dilatometers that could be installed in a Quantum Design Physical Properties Measurements System (PPMS) were developed. Two types of dilatometers were constructed. One dilatometer was compact enough to be installed in small magnet bore of various cryostats and had a reference capacitor so that high sensitivity and stability were achieved. The other dilatometer with a movable capacitor supported by a flat spring enabled to measure large strain and exchange samples easily. We measured the thermal expansion and magnetostriction of single crystalline clathrate compound Pr3Pd20Ge6 and polycrystalline hydrogenated La(Fe0.88Si0.12)(13) in the temperature range between 2 and 340 K and magnetic field up to 8 T. The dilatometers allowed to detect the strain responses with a sensitivity of 10 ppb. We could measure strain from 10(-8) to 10(-3) using two dilatometers.