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Dielectric properties characterization of La- and Dy-doped BiFeO3 thin films

Published online by Cambridge University Press:  31 January 2011

Peter Kr. Petrov*
Affiliation:
Imperial College, London SW7 2AZ, United Kingdom
Vaijayanti R. Palkar
Affiliation:
Tata Institute of Fundamental Research, Mumbai 400005, India
Alexander K Tagantsev
Affiliation:
Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL), Lausanne CH-1015, Switzerland
Hsin-I Chien
Affiliation:
London South Bank University, London SE1 0AA, United Kingdom
K. Prashanthi
Affiliation:
Indian Institute of Technology Bombay, Mumbai 400076, India
Anna-Karin Axelsson
Affiliation:
Imperial College, London SW7 2AZ, United Kingdom
S. Bhattacharya
Affiliation:
Tata Institute of Fundamental Research, Mumbai 400005, India
Neil McN Alford
Affiliation:
Imperial College, London SW7 2AZ, United Kingdom
*
a)Address all correspondence to this author. e-mail: p.petrov@imperial.ac.uk
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Abstract

The dielectric response of La- and Dy- doped BiFeO3 thin films at microwave frequencies (up to 12 GHz) has been monitored as a function of frequency, direct current (dc) electric field, and magnetic field in a temperature range from 25 to 300 °C. Both the real and imaginary parts of the response have been found to be non-monotonic (oscillating) functions of measuring frequency. These oscillations are not particularly sensitive to a dc electric field; however, they are substantially dampened by a magnetic field. The same effect has been observed when the volume of the characterized sample is increased. This phenomenon is attributed to the presence of a limited number of structural features with a resonance type response. The exact origin of these features is unknown at present. Leakage current investigations were performed on the whole set of films. The films were highly resistive with low leakage current, thereby giving us confidence in the microwave measurements. These typically revealed ‘N’-type I-V characteristics.

Type
Articles
Copyright
Copyright © Materials Research Society 2007

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References

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