Structural and electrical behavior evaluation of Ho-substituted Co₂W hexagonal ferrites

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• 作者：Faiza Aen^a ; ^{optimist8@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; M.F. Wasiq^a ; M.U. Rana^a ; Hasan M. Khan^a ; Muhammad Azhar Khan^b ; ^{azhar.khan@iub.edu.pk" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Nano-structured ferrites ; XRD ; FTIR ; Sol-gel ; SEM ; Electrical properties
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：1 November 2016
• 年：2016
• 卷：42
• 期：14
• 页码：16077-16083
• 全文大小：1675 K

文摘

Holmium (Ho³⁺) substituted W-type hexagonal ferrites (BaCo₂Fe₁₆O₂₇) were prepared by sol gel auto-combustion technique. The precursors were prepared by Ba²⁺, Fe³⁺ nitrates solutions with citric acid as chelating agent. The prepared powder was sintered at 950 °C for 8 h to produce a single phase of W-type hexa ferrite with corresponding crystallite size ranging from 34 nm to 44 nm. The thermal decomposition of nitrate-citrate gel of as-prepared powder was investigated by TGA and DTA. The FTIR spectral study reveals the presence of two absorption bands which are characteristics of hexaferrites. DC electrical resistivity increases from 3.01×10⁹ to 5.69×10¹⁰ (ohm-cm). The real and imaginary parts of dielectric constant (ɛʹ, ϵ״) and dielectric loss tangent (tan δ) are determined in the frequency range of 20 Hz–1 MHz. It was observed that both real and imaginary parts of the dielectric constant and tanδ decrease with the increase of frequency on the basis of Wagner and Koop's theory.