R. P. Aloysius

Establishement of the magnetic flux density standard in the range 100 µT to 1000 µT

The magnetic flux density standard in the range 100 µT to 1000 µT has been established using a standard Helmholtz coil. The ambient magnetic field including earths magnetic field components inside the room and other noises has been compensated to a level of the order of 100 nT. A circular triaxial Helmholtz coil pair of size nearly 800 mm has been used for compensating the ambient magnetic field. The standard Helmholtz coil of size 300 mm has been placed in the geometrical centre of the triaxial Helmholtz coil pair. The magnetic flux density has been measured using triaxial and single axis fluxgate magnetometers. The coil constant of the standard Helmholtz coil has been found to be 850.6808 ± 0.0036804 µT/A, which is in good agreement with the manufactures specification viz, 850 µT/A, with an uncertainty of < ± 0.5 %.

Synthesis And Characterization Of Cadmium Doped Lithium Ferrite By Sol‐gel Technique

Cadmium substituted lithium ferrite Li0.5−x/2CdxFe2.5−x/2O4 were prepared by sol‐gel method. Saturation magnetization versus composition shows a maximum Ms = 80 emu/g at for = 0.3. In all samples, dielectric constant decreases with increasing frequency while dielectric loss tangent first increases and attains a maximum value followed by a decrease. Dielectric constant is in the range of 105 for sample x = 0.1 & 0.3 with a low dielectric loss. High dielectric constant and low dielectric loss are essential requirement of ferrite for power applications.