Charge ordering transition in (La, Pr)1/3Sr2/3FeO3−δ with different oxygen concentration investigated by mechanical spectroscopy
1 National Laboratory of Solid State Microstructures and School of Physics, Nanjing University Nanjing 210093, China
2 Collaborative Innovation Center of Advanced Microstructures - Nanjing 210093, China
Received: 15 March 2015
Accepted: 27 April 2015
We present the results of the kilohertz mechanical spectrum of oxygen-varied La1/3Sr2/3FeO3−δ and Pr1/3Sr2/3FeO3−δ. On cooling, a substantial modulus softening above the charge ordering transition temperature TCO, and an abrupt stiffness and step-like decrease of the internal friction below TCO were observed in oxygen stoichiometric La1/3Sr2/3FeO3−δ. No step-like change of the mechanical spectrum was observed in charge-ordered Pr1/3Sr2/3FeO3−δ, which shows the absence of dynamic Jahn-Teller distortions in Pr1/3Sr2/3FeO3−δ. Another modulus softening below was observed in charge-ordered (La, Pr)1/3Sr2/3FeO3−δ, which was used to discriminate the charge ordering transition from the charge disproportionation transition in perovskite iron oxides.
PACS: 62.40.+i – Anelasticity, internal friction, stress relaxation, and mechanical resonances / 71.30.+h – Metal-insulator transitions and other electronic transitions / 81.40.Jj – Elasticity and anelasticity, stress-strain relations
© EPLA, 2015