TlSr2NiO4+delta has been synthesised by reaction of Tl2O3 and Sr2Ni2O5
in a sealed gold tube at 950 degrees C. The compound is isostructural
with the orthorhombic form of T1Sr(2)CuO(4+delta) with alternating Tl
O and oxygen-deficient (NiO2-x) layers.