Case Studies
S V Soni, C L Khobragade , R K
Abstract
Two new series of W type hexaferrites with the composition Ba 2+ Sr 2+ 2 (Ni 2+ x/2. Znx 2+) Fe 3+ 16-x O -2 27 (x=0.1 to 0.4) and Co 2+ Sr 2+ 2 (Ni 2+ x/2. Zn 2+ x) Fe 3+ 16-x O -2 27 (x=0.2 to 0.8) were prepared using co precipitation technique . The precipitate was calicinated at 1100 o C for 4 hours and characterization was carried our using X-Ray technique. The values of “a” for the samples investigated lies in the range 5.8347 Å to 5.8755 Å and c= 33.1327 Å to 33.3587 Å. They match well with the values reported by Sawadh and Kulkarni [1]. The effect of calcinations temperature and parameters involved during production on the structure and average particle size of the grown samples has been studied. It is conjectured that these do not have any predominant effect on the average particle size and its structure. However, the composite formed shows an increase in the grain/ particle size with the increase in the doping concentration. From the X-RD studies it is established that a W-type hexagonal phase is formed when the mixtures of [Ba 2+ Sr 2+ 2 (Ni 2+ x/2. Zn 2+ x) Fe 3+ 16-x O -2 27] (x=0.1 to 0.4) and [Co 2+ Sr 2+ 2 (Ni 2+ x/2. Zn 2+ x) Fe 3+ 16-x O -2 27 ] (x=0.2 to 0.8) are sintered at 1100 o C and diphase composite ferrite that consists of Co and Ba spinal ferrite and a composite W type hexaferrite is finally obtained.