Fabrication of Mg 1-X Zn X Fe 2 O 4 (where x = 0.2, 0.3, 0.4 and 0.5) samples using a conventional technique is reported. Oxides of magnesium, zinc and iron with purity of about 99.99% were mixed with distilled water in a milling machine for 12 hours. They were then filtered and presintered at 1250°C and sintered at 1350°C for 10 h in air. The phase and the crystal structure of the asprepared samples were identified using X-Ray Diffraction analysis (XRD). Hysteresis graph was evaluated using Vibrating Sample Magnetometer (VSM) to get the saturation magnetization (emu g −1 ) and coercivity (G) value. Atomic Force Microscope (AFM) was used to observe the surface morphology. The X-ray diffraction analysis showed major peak at plane (3 1 1) of the cubic structure for all the ferrites. The largest value of density achieved was 4.69 gcm −3 which was exhibited by sample with 0.5 mole fraction of zinc content. Highest saturation magnetization value (3.652emu g −1 ) was obtained for the 0.3 mole fraction of zinc content. A strong correlation between the saturation magnetization and zinc content was observed. We speculate that it is due to the Heisenberg superexchange interaction of magnetic Fe 3+ and non-magnetic Zn 2+ occupying the tetrahedral sites. The sample was used to induce electromagnetic (EM) waves in high operating frequency (5 MHz).

This study presents a concept of harvesting and transferring energy to a low power electrical appliances using wireless technology where interconnecting wires are not available. This study was a ground work for the future alternative energy supply especially to the areas where supplying direct energy is a challenge such as in deep sea exploration as well as to the area where power interruption is a problem. Research was carried out to study how the waste signal and energy in the air could be collected and converted into useful energy which later could be used to supply power to electrical appliances. The approach of this research started by simulation work using PSPICE full edition that was performed to develop the design and later was used as guidelines in developing the prototype. We then harvested the Radio Frequency (RF) signal that was available in air by using RF energy harvesting circuit. This circuit harvested the energy and converted them into electricity. It was accomplished by using an antenna to capture the RF energy and a voltage doublers circuit to convert and magnify the AC input signal to larger DC output. For a start we managed to capture a 3V voltage which was stored in a rechargeable battery. The energy in this rechargeable battery was then utilized to power up low-powered electrical appliances. Germanium and Silicon diodes have been used to harvest and amplify the voltage so that a better and higher output can be achieved.