High-temperature dilatometric studies on the (RE)BaCuO system (RE = Y,Nd)

Thermal expansion measurements have been carried out using dilatometry on the (RE)BaCuO system in the temperature range 300–1100 K. The peak in the thermal expansion coefficient (α) at 890 K presages the high-temperature orthorhombic-to-tetragonal phase transition in $YBa_2Cu_3O_{7-\delta}$. The thermal expansion behaviours of $YBa_2Cu_3O_{7-\delta}$, $Y_2BaCuO_5$, $NdBa_2Cu_3O{7-\delta}$ and $Nd_4Ba_2Cu_2O_{10}$, which are the constituent phases of melt-processed high-$J_c$ superconducting ceramics, are compared. The relevance of dilatometric studies at high temperature to such multiphase ceramic bodies is discussed