“STRUCTURAL PROPERTIES OF HOLMIUM DOPED COBALT FERRITE BY STANDARD CERAMIC TECHNIQUE”

Objective: Compositions of CoHoxFe2-xO4 (x = 0.00 and 0.02) was prepared by standard ceramic technique using AR grade CoO2, Ho2O3 and Fe2O3. The samples were characterized by X-ray diffraction technique and the analysis of XRD patterns reveals the formation of single phase cubic spinel structure. The structural parameters like lattice constant (a), x- ray density(dx), bulk density (dB), particle size (t) and porosity (P), tetrahedral and octahedral bondlength (dAX and dBX), the tetrahedral edge (dAXE), and the shared and unshared octahedral edge (dBEX and dBXEU) can be calculated were calculated form XRD data and effect of Ho3+ doped cobalt ferrite was studied. Thus, the rare earth Ho3+ doped cobalt ferrite strongly influences the physical properties of cobalt ferrite. Materials and Methods: Present series was prepared by standard ceramic technique using AR grade CoO2, Ho2O3 and Fe2O3. Results: The XRD pattern shows that both the samples possess single phase cubic spinel structure. No extra peak of Ho3+ is observed for x =0.02 sample. Lattice constant, X-ray density of Ho3+ doped cobalt ferrite is increases than that of pure cobalt ferrite. Conclusion: The rare earth Ho3+ doped cobalt ferrite strongly influences the physical properties of cobalt ferrite

ELECTRICAL CONDUCTION, dielectric BEHAVIOR AND MAGNETOELECTRIC EFFECT IN (1-x) Co1.2Mn0.2Fe1.6O4 + (x) BaTiO3 ME Composites

Objective: Electrical and magnetoelectric properties of magnetoelectric (ME) composites ferroelectric as electric component and a mixed ferrite as magnetic component are reported. The (1-x) Co1.2Mn0.2Fe1.6O4 + (x) BaTiO3 magnetoelectric (ME) composite have been prepared using conventional double sintering ceramic process where x varies as 0.00, 0.25, 0.50, 0.75 and 1.00. The X-ray diffraction pattern of the composites reveals the formation of spinel structure for the piezomagnatic phase and tetragonal perovskite structure for the piezoelectric phase without any other phase formation. The dc resistivity was measured as a function of temperature. The variation of dielectric constant ' dielectric loss ε'' and dielectric loss tangent δ with frequency in the range 1kHz-1MHz was studied. The dielectric constant shows dispersion in the lower frequency region, with almost a constant value at higher frequencies. The magnetoelectric voltage coefficient (dE/dH)H was studied as a function of intensity of the magnetic field. The measured magnetoelectric (ME) response demonstrated strong dependence on the volume fraction of CoMnFe2O4 and the applied magnetic field. A large ME voltage coefficient of about 647 Vcm-1Oe-1 was observed for 25% CoMnFe2O4 + 75% BaTiO3composite. Materials and Methods: The piezoelectric phase Barium Titanate (BaTiO3) was prepared by standard doubling sintering ceramic method using AR grade oxides/carbonate. Barium carbonate (BaCO3) and Titanium-dioxide (TiO2) were taken in molar proportion. Results: The electrical resistivity of ferrite phase is less as compared to the resistivity of ferroelectric material. The resistivity of composites is found to be in between ferrite and ferroelectric. Conclusion: Magneto-electric conversion factor with varying magnetic field shows maxima in the curve at a lower magnetic field and then decreases continuously at higher magnetic field. As ferroelectric content increases both the resistivity and magnetoelectric conversion factor also increases

Surface rainwater harvesting potentiality and impact of Dhaval micro-watershed in Satara district, Maharashtra, India

The main objective in constructing the rainwater harvesting structures is to collect and retain the maximum possible amount of runoff generated from its catchment area. If suitable small surface water harvesting structures are taken up systematically on a micro-watershed basis, it is possible to avoid the drought like conditions that prevail in semi-arid regions. The present paper based on the primary data collected by conducting intensive fieldwork and personal interviews. It is found that three main surface water harvesting structures have been constructed. These are - i) Cascade of tanks and contour bunds ii) Networking of farm ponds iii) percolation tank. It is suggested that such surface rainwater harvesting structures should be constructed in a micro-watershed particularly in the drought-prone areas to bring prosperity and development. Key Words: Water harvesting, Potentiality, Micro-watershed, Impact, Sustainable development