ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The spin-spray plating (SSP) is an equilibrium chemical process with which spinel ferrite films can be grown on a variety of substrate materials at temperatures as low as 100 °C. The process is particularly attractive for the monolithic integration of microwave magnetic and electronic GaAs devices. The study of the electrical characteristics of these films is part of an effort aimed at achieving this integration. Low-loss microwave magnetic devices require that the materials used have dielectric loss tangents (tan δ) on the order of 0.001 or lower, and dc resistivities greater than 107 Ω cm. In the SSP process, control of the chemical composition of the films is limited by an incompatibility of desirable transition metal ions (e.g., Fe,Ni,Zn,Mn) with the tetrahedral and octahedral cation sites available in the spinel structure. Therefore, the substitution of a specific cation modifies the site distribution of other ions in the spinel lattice. The overall distribution of the metallic cations determines the electrical and magnetic properties of the ferrite films. Specifically, low resistivity is due to the mixtures of high- and low-valence cations of a metal element in the same lattice site. In this study Ni-Zn ferrite films were produced with resistivities ranging from 10 to 106 Ω cm. Dielectric loss tangents measured, however, were several orders of magnitude higher than desired. Predictably, the loss tangent decreases monotonically with increasing resistivity; however, its values are much higher than the literature values for ceramic ferrites and semiconducting materials for the same range of dc resistivities. The reasons for this are presently being investigated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.345875
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