a1 Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
Elastic modulus and internal friction of Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) and La0.58Sr0.4Co0.2Fe0.8O3-δ (LSCF) were determined from resonance frequencies and damping behavior, respectively, using an impulse excitation method. An elastic anomaly for BSCF around 476 K, with a corresponding peak in the internal friction, is attributed to the experimentally confirmed spin transition of Co3+. LSCF is in a ferromagnetic state below ∼220 K and in a paramagnetic state above ∼250 K. The elastic modulus of LSCF exhibits an anomaly between 473 and 1113 K, which is attributed to a transition from rhombohedral to cubic symmetry.
(Received December 16 2010)
(Accepted May 03 2011)
(Online publication June 10 2011)