Dielectric relaxation and polaronic hopping in Al-substituted Sm1.5Sr0.5NiO4 ceramics

• Published in: Journal of physics. D, Applied physics Applied physics, 2010-12, Vol.43 (49), p.495402-495402
• Main Authors: Liu, Xiao Qiang, Jia, Bo Wen, Yang, Wen Zhi, Cheng, Ji Peng, Chen, Xiang Ming
• Format: Article
• Language: English
• Subjects: Adiabatic flow; Aluminium; Aluminum; Ceramics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity phenomena in semiconductors and insulators; Correlation; Dielectric loss and relaxation; Dielectric properties of solids and liquids; Dielectric relaxation; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electrical conduction; Electronic transport in condensed matter; Exact sciences and technology; Mobility edges; hopping transport; Orthorhombic phase; Permittivity (dielectric function); Physics
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/43/49/495402

The structure and dielectric properties of Sm1.5Sr0.5Ni1-xAlxO4 (x = 0.,0.5) ceramics were presented. A single orthorhombic phase was obtained in Sm1.5Sr0.5Ni0.7Al0.3O4 ceramics, while minor impurities existed in Sm1.5Sr0.5Ni0.5Al0.5O4 ceramics. Temperature stable giant dielectric response was observed in these two ceramics, and only one dielectric relaxation was found. After comparing the activation energies of dielectric relaxation and electrical conduction, the giant dielectric response should be attributed to the adiabatic small polaronic hopping process, and the dielectric behaviour of the samples with different aluminium contents confirmed the correlation between the dielectric response and electrical conduction.