Structural and magnetic properties of Dy3+ doped Y3Fe5O12 for microwave devices

The Dy3+ doped Y3−xDyxFe5O12 (x=0–3) nanopowders were prepared using microwave hydrothermal route. The structural and morphological studies were analyzed using transmission electron microscope, X-ray diffractometer and field emission scanning electron microscope. The nanopowders were sintered at 900 °C/90 min using microwave furnace. Dense ceramics with theoretical density of around 95% was obtained. Ferro magnetic resonance (FMR) spectrum and microwave absorption spectrum of Dy3+ doped YIG were studied, the signal exhibits a resonance character for all Dy3+ variations. It was observed that the location of the FMR signal peak at the field axes monotonically shifts to higher field with increasing Dy3+ content. The dielectric and magnetic properties (ε′, ε′′, µ′ and µ′′) of Dy3+ doped YIG were studied over a wide range of frequency (1–50 GHz). With increase of Dy3+ both ε′ and µ′ decreased. The low values of dielectric, magnetic properties and broad distribution of FMR line width of these ceramics are opening the real opportunity to use them for microwave devices above K- band frequency.