Study of dielectric relaxations in co-precipitated Sr–Fe(Cr) nanoferrites

• Published in: Journal of materials science. Materials in electronics 2015-09, Vol.26 (9), p.6539-6545
• Main Authors: Anis-ur-Rehman, M., Fatima-tuz-Zahra, Kanwal, Seemab, Khan, Zeenat, Asif, Anila, Hussain, Anam Noor, Zahid, Saba
• Format: Article
• Language: English
• Subjects: Alternating current; Characterization and Evaluation of Materials; Chemistry and Materials Science; Chromium; Coprecipitation; Dielectric loss; Materials Science; Nanostructure; Optical and Electronic Materials; Resistivity; Strontium; X-ray diffraction
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-015-3250-6

Chromium (Cr) doped strontium hexaferrites with nominal composition SrFe 12−x Cr x O 19 (x = 0.0, 0.1, 0.2, 0.3) were prepared using co-precipitation method. Thermal analysis of the samples was carried out using thermogravimetric analysis and differential scanning calorimetry to study the thermal stability as well as the transitions within the samples with variation in temperature. Structural analysis of the samples was carried out using X-ray diffraction (XRD). XRD revealed that all the samples possess hexagonal structure with space group P63/mmc. AC electrical properties including dielectric constant ( έ ), dielectric loss tangent (tan δ ) and ac electrical conductivity ( σ ac ) were studied as a function of frequency (1 kHz–3 MHz) at temperatures 100–700 °C. The dielectric losses tend to decrease with increasing Cr content. AC conductivity could be very well explained by Jonscher power law. These materials have applications in high frequency devices with reduced energy losses.