Dy. Jung et al., PREPARATION AND CHARACTERIZATION OF NEW PEROVISKITES CONTAINING IR(VI) AND IR(V) [BAM0.50IR0.50O.275 AND BAM0.25IR0.75O3 (M=LI OR NA)], Materials research bulletin, 30(1), 1995, pp. 113-123
New Ir(VI) and Ir(V) containing perovskites oxides of the type, BaM0.5
Ir0.5O2.75 and BaM0.25Ir0.75O3 (M = Na or Li) have been synthesized un
der high oxygen pressure conditions using the thermal decomposition of
KClO3 in a belt apparatus. These materials have been characterized by
X-ray diffraction, iodometric titration, and magnetic susceptibility
measurements. BaM0.25Ir0.75O3 (M = Na,Li) phases do not show 1:3 type
ordering of M and Ir cations at the octahedral sites of the perovskite
structure. The physico-chemical characterization of the prepared irid
ium perovskites show that the structure depends on synthetic condition
s employed, the oxidation state of iridium and the coordination of Ir(
n+) (n = 5, 6). The ionic radii of the counter cations, M (Na or Li),
also play an important role in the stabilization of a particular struc
ture by altering the tolerance factor.