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The substituted Y type hexaferrites Sr 2 Zn 2 Al Fe 12− O 22 (where = 2, 4, 6, 10) are prepared by standard ceramic technique. The infrared absorption spectra of the prepared compounds are studied in the range 400 cm −1 to 4600 cm −1. These spectra are used to locate the vibrational ranges due to substituted cations with the nearest oxygen layers and also to understand the band positions attributed to the lattice sites. The absorption regions found around 460 cm −1 and 600 cm −1 are the common features of all spinel ferrites. Both X-ray and IR spectroscopic studies in these ferrites do not detect the presence of Fe 2+. Also with increase in aluminium substitution, the higher frequency bands start disappearing. This may be due to reduced vibrations of trivalent cations Fe-O bonds at both octahedral and tetrahedral sites which in turn affect Fe 3+-O 2−-Fe 3+ superexchange interactions present in the structure.

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Series of polycrystalline samples of Zn 2-x Cu x Ba Fe 16 O 27 were prepared by usual ceramic methods, where (x=0.0, 0.4, 0.6, 0.8, 1.0, 1.4). X-ray analysis were obtained at room temperature using α Cok with 0 790. 1 A = λ confirmed the presence of W-type hexaferrite phase structure. Saturation magnetization and hysteresis loops curves measurements at room temperature were studied as a function of + 2 Cu substitution. It can be seen that the + 2 Cu content slightly decreases the saturation magnetization from 25 to 20 (emug-1), all hysterysis loops are closed which indicates low anisotropy field and low saturation magnetization field. The dc conductivity and thermoelectric power was measured in range from room temperature up to T = 750 K for all samples. The thermoelectric power decreases by increasing + 2 Cu content and the conductivity increases with temperature. The value of the charge carrier concentration increases by increasing temperature and + 2 Cu content .