Magnetostriction of polycrystalline YNi2B2C samples in the superconducting state

Flux pinning in type II superconductors causes characteristical hysteresis in length change when a magnetic field greater than the lower critical field BC1 is applied to the sample and then reversed. Results on yttrium nickel borocarbide polycrystalline samples using capacitive dilatometry are reported. Magnetostriction measurements in the temperature range from 1.5 K to 24 K reveal that homogeneous flux distribution is reached at temperatures and fields lower than the upper critical field BC2(T). (orig.)