The ordered K2NiF4-type structure of mixed crystals La2-xSrxLi1/2Co1/2O4 (x < 0.5) and the electronic properties of the constituting Co-III and Co-IVions
Sa. Warda et al., The ordered K2NiF4-type structure of mixed crystals La2-xSrxLi1/2Co1/2O4 (x < 0.5) and the electronic properties of the constituting Co-III and Co-IVions, J SOL ST CH, 146(1), 1999, pp. 79-87
Solids of the composition La2-xSrxLi1/2Co1/2O4 (x = 0, x congruent to 0.2)
crystallize in a superstructure of the K2NIF4 lattice with a doubled unit c
ell in the (001) plane (space group Ammm; a = b = root 2a(0)), caused by ca
tion ordering between lithium and cobalt on the octahedral sites. The elect
ronic structure of the (CoO6)-O-III and (CoO6)-O-IV polyhedra, which lie is
olated in the lattice, were studied by various spectroscopic techniques (XA
NES, EPR, optical). The groundstates are low-spin in both cases (t(2g)(6) a
nd t(2g)(5), respectively), the ligand field parameters of Com being close
to those characterizing the high-spin/low-spin crossover. (C) 1999 Academic
Press.