Kausar Javed Khan
Lahore College for Women University, Pakistan
Title: Comprehensive study of chemical synthesis and dielectric parameters of holmium substituted yttrium iron garnets (HoxY3-xFe5O12, x=0.1, 0.3, 0.6, 0.9, 1.2, 1.5) prepared by conventional ceramic method
Biography
Biography: Kausar Javed Khan
Abstract
YIG (yttrium iron garnet) is magnetic ferrite having chemical formula Y3Fe5O12 and high resistivity. Substituted YIGs have formula RexY3-x Fe5O12, where R represents rare earth elements. Polycrystalline cylindrical (13 mmx3.3 mm) six samples of holmium substituted YIG (HoxY3-xFe5 O12) were prepared by conventional ceramic technique. Powder samples were annealed at 10000C (1 hour) and these were called green powders. The crystalline structure and dielectric properties of samples were studied by D8 Discover X-Ray diffractometer and Wayne Kerr impedance analyzer. Microstructural properties like crystallite size, dislocation density, micro-strain were calculated using XRD data. Increase in crystallite size was observed with the increase of holmium composition. Decreasing trend in dislocation density was observed with the increasing holmium contents. Dielectric parameters were studied with reference to changing holmium composition and changing frequency comprehensively. Both dielectric constant (∈) and dielectric loss (∈) decreased sharply with the increase of frequency at room temperature (300k).The decreasing trend in dielectric parameters was observed with the increase in holmium contents. This series of substituted YIG having small dielectric constant, low dielectric loss and negligible tangent loss can play the most vital role in many electronic devices in microwave region. Small dielectric parameters exhibited by these prepared magnetic garnets make them highly useful in telecommunication and defense industry.
Recent Publications
- Anjum Qureshi, (2009) “Dielectric and magnetic properties of YIG/PMMA nano composites” Journal of Physics, Conference Series, 153 (2009) 012061.
- Rased M.M., Hossien M.M., Midany A.El, Ibrahim I.A. (2009) “Effect of synthesis conditions on the preparation of YIG powders via co-precipitation method,” J.Magn. Magn. Magn. Mater.
- Nimbore S.R., Shengule D.R., Shukla S.J., Bichile G.K., Jadhav K.M., (2006) “Magnetic and Electrical Properties of Lanthanum substituted Yttrium Iron Garnets” J.Mater. Sci, Vol. 41, pp 6460-6464.
- Huang C., Zhang Q. (2004) “Enhanced dielectric and Electrochemical responses in high dielectric constants of all polymer percolative composites,” Adv. Funet. Matter, Vol. 14, pp 501.
- Sozeri H., Ghazanfar N., ( 2009) “Another alternative to the Solid State Reaction method to synthesis nanocrystalline YIG, Ammonium Nitrate Melt technique,” J. Physics Conference, pp 153.