Premium
Processing of Nickel–Zinc Ferrites Via the Citrate Precursor Route for High‐Frequency Applications
Author(s) -
Verma Anjali,
Dube Dinesh C.
Publication year - 2005
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2005.00098.x
Subject(s) - materials science , permittivity , curie temperature , sintering , dielectric , ceramic , analytical chemistry (journal) , electrical resistivity and conductivity , ferrite (magnet) , dielectric loss , nickel , zinc , magnetization , mineralogy , nuclear magnetic resonance , condensed matter physics , metallurgy , ferromagnetism , composite material , chemistry , magnetic field , optoelectronics , electrical engineering , physics , engineering , chromatography , quantum mechanics
Nickel–zinc ferrites of various compositions, Ni 1− x Zn x Fe 2 O 4 where x =0.2, 0.4, 0.5, and 0.6 investigated in the present work, have been prepared by the citrate precursor method. The complex permittivity (∈′− j ∈″) and permeability (μ′− j μ″) of the ferrites were measured at X‐band (8–12 GHz) microwave frequencies. The dielectric constants or the real part of permittivity, ∈′, are observed to lie in the range 5.46–8.95 for ferrites sintered at 1200°C, while those sintered at 1300°C exhibit relatively higher dielectric constants. The permittivity loss, tan δ ∈ (=∈″/∈′), is observed to be of the order of 10 −2 –10 −3 , depending upon the composition and sintering temperature of the ferrite. These losses are lower by at least one to two orders of magnitude compared with those normally reported for ferrites processed by the conventional ceramic method. The presently studied ferrites also exhibit high values of DC‐resistivity, 10 7 –10 11 Ω·cm. The low dielectric losses and high resistivity can be co related to small grain size and better compositional stoichiometry obtained as a result of processing via the citrate route. Magnetic properties such as the Curie temperature, saturation magnetization, initial permeability, and B – H hysteresis parameters of the compositions with x =0.5 and 0.6 are also given.