Low temperature sintering of iron deficient Z type hexagonal ferrites

摘要

Low temperature sintering of iron deficient hexagonal Co_2Z type ferrites is attempted to prepare a chip inductor for ultra high frequency uses. It should be attained below the melting point of silver (960 deg C) used as the electrode material of the chip inductor. The best result is obtained for the sample with the composition 2.15Co_(0.6)Cu_(0.4)O centre dot 3Ba_(0.79)Sr_(0.16)Bi_(0.05)O centre dot 9.725Fe_2O_3 sintered at 925 deg C containing 0.5 wt.percent of lithium bismuth oxide as a sintering additive. Its density and permeability reaches 5.0 g/cm~3 and 7, respectively. As a result, the impedance of the chip inductor also reaches 390 ohm at 2 GHz using this material.