Study of complex impedance spectroscopic properties of La0.7−xDyxSr0.3MnO3 perovskite oxides

Abstract

The dysprosium perovskite La0.7−xDyxSr0.3MnO3 (x = 0.00 [LSMO] and 0.03 [LDSMO]) compounds were prepared by the sol–gel reaction and characterized by the X-ray diffraction technique. The electrical conductivity and modulus characteristics of the system have been investigated in the temperature and the frequency range 311–356 K and 209–5 × 107 Hz, respectively, by means of impedance spectroscopy. The ac and dc conductivities were studied to explore the mechanisms of conduction of LSMO and LDSMO. The insertion of a small amount of Dy3+ in the La-site of LSMO perovskite oxide increases the value of the activation energy from 0.2106 to 0.5357 eV and enhances electrical resistivity values for almost two orders of magnitude.

Keywords

• impedance spectroscopy
• ac conductivity
• modulus
• the non-overlapping small polaron tunneling
• correlated barrier hopping