The high‐frequency magnetic properties of strontium‐partially‐substituted Z‐type magnetoplumbite with the composition 2CoO·3Ba1‐x.SrxO.yFe2O3 were studied using a hot‐pressing technique. The best properties were obtained for a sample hot‐pressed in oxygen, having x and y values of 0.5 and 10.8, respectively. The resonant frequency of that sample, corresponding to a μ” maximum reaching 2.5 GHz, was significantly larger than the value of 1.4 GHz previously reported for unsubstituted Z with the composition 2CoO·3BaO·12Fe2O3. This result implies that a new ferrite material, applicable in the gigahertz region, has been obtained.

Methyl methacrylate, ethyl methacrylate, propyl methacrylate, and styrene were graft-polymerized onto the amorphous polyamide poly(hexamethylene terephthalamide/isophthalamide) (SELAR). Membranes were prepared from the modified SELAR and unmodified SELAR. The membranes were permeated benzene in preference to cyclohexane from benzene/cyclohexane mixtures by pervaporation.

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