Negative thermal expansion of HTSC-type structures: low temperature structure measurements on Eu1+x(Ba1−yRy)2−xCu3O7−d compounds and theoretical treatment

Abstract

The temperature dependences of the lattice parameters were investigated on the perovskite-like structures Eu 1+x (Ba 1-y R y ) 2-x Cu 3 O 7-d with Ba substitution by light rare earth, using x-ray diffraction techniques. A negative thermal expansion effect was observed and explained in detail.