Thermal expansion of layered cobaltites Y(Ba1−x Srx )Co2O5+δ with x = 0, 0.05 and 0.10

AURELIO, G.; BUSTINGORRY, S.; SÁNCHEZ, R. D.; CUELLO, G. J.

JOURNAL OF PHYSICS CONDENSED MATTER

IOP PUBLISHING LTD

Lugar: Londres; Año: 2011 vol. 23 p. 3154031 - 3154039

0953-8984

The crystal structure and thermal expansion of Sr-doped layered cobaltites Y(Ba1 − xSrx)Co2O5 + δ (x = 0, 0.05 and 0.10) were studied by means of in situ neutron thermodiffraction in the temperature range 20 K ≤ T ≤ 570 K. The evolution with temperature of lattice parameters for the phases which crystallize in this system is presented, as well as their dependence on the oxygen non-stoichiometry δ. Each phase´s volume has been fitted using available models based on the Grüneisen approximation to the zero-pressure equation of state and using the Ruffa model based on the Morse potential, both using a Debye model for the internal energy. The coefficient of volumetric thermal expansion, Debye temperature and other thermodynamic parameters are presented and compared with other perovskite compounds.