MAGNETIC AND CALORIMETRIC STUDIES OF GD ORDERING IN TLBA2GDCU2O7-DELTA

Antiferromagnetic ordering among Gd3+ ions in the nonsuperconducting c ompound TiBa2GdCu2O7-delta occurs near 2.2-2.3 K as confirmed by magne tic and calorimetric measurements. This compound is similar in structu re to that of superconducting GdBa2Cu3O7-y, but with the Cu-O chains r eplaced by Tl-O planes, which also exhibits a similar magnetic transit ion at 2.2-2.3 K. This paper further compares the Neel temperatures an d magnetic specific-heat anomalies of various Gd-containing compounds and related systems. Some common features between the compounds are di scussed.