Studies on dielectric relaxation in ceramic multiferroic Gd1−xYxMnO3 |
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Authors: | Sarguna Ramaiyan Mahadevan Sridharan Varadarajan Anand Mohan Awasthi Subramanian Natarajan |
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Affiliation: | 1. Condensed Matter Physics Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India;2. Thermodynamics Laboratory, UGC‐DAE Consortium for Scientific Research, University Campus, Indore, India |
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Abstract: | Dielectric study over a broadband was carried out from 10 to 70 K on ceramic Gd1?xYxMnO3 (x=0.2, 0.3 and 0.4). For all the compositions, a prominent sharp peak about ~18 K was observed in the temperature dependence of both ε′(T) and ε″(T) at all frequencies, indicating a long‐range ferroelectric (FE) transition. Using Cole‐Cole fit to the permittivity data, the relaxation time τ and the dielectric strength ?ε were estimated. Temperature variation of τ(T) in the Arrhenius representation is found to be nonlinear (non‐Debyean relaxation), with increasing barrier‐activation energy over successive temperature‐windows. Interestingly, for all the compositions, we witness a jump in τ(T) about the ferroelectric transition temperature, concurred by a broad‐maximum in ?ε(T),signifying the critical slow down of relaxations near long‐range FE‐correlations. |
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Keywords: | dielectric relaxation ferroelectricity/ferroelectric materials low temperature multiferroics |
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