Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

2 Electron Technology

2 1998

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Structure and magnetic properties of polycrystalline YIG garnets and circulator design in microwave frequencies

100%

Park J. R. , Kim T. H. , Choy T. G.

tom Vol. 31, No. 1

114-119

Yttrium Iron Garnet (YIG) ceramics are isolators, circulators, phase shifters, etc. in high frequency telecommunication systems. In this paper the effect of Al₂O₃ substitution on the micro-stucture and the magnetic properties of YIG with Ca, Sn substitutions were studied. The specimen was prepared with convenational ceramic method and analyzed using scanning electron microscopy, X-ray diffractometry, magnetometry and ferrimagnetic resonance experiments. The effect of Al₂O₃ substitution on the permittivity and permeability of YIG with Ca, Sn substitutions was measured using the cavity perturbation method in microwave frequencies. The YIG specimen with 1.2 mol% Al₂O₃ was sintered at 1450°C. It showed ferrimagnetic resonance linewidth ∆H of 42 Oe and saturation magnetization 487 G. The measured permittivity and permeability in the microwave range were 15.623 and 0.972, respectively. The fabricated strip-line junction circulatior using the above YIG ceramics had the insertion loss of 0.406 dB, return loss of 19.272 dB and isolation of 17.848 dB at the center frequency of 1.855 GHz.

The effects of sintering additives on sinterability and microwave properities of yttrium iron garnet

88%

Kim W. T. , Song Y. Y. , Yu S. C. , Park J. R. , Lee S. S.

tom Vol. 31, No. 1

121-128

The effects of small addition of either Bi₂O₃ or a mixture of CuO + B₂O₃ on sinterability and microwave properties of yttrium iron garnet (YIG), prepared using a conventional ceramic method, have been studied by means of scanning electron microscopy, X-ray diffractometry, magnetometry and ferromagnetic resonance experiments. Sintering temperature for YIG could be reduced by about 50 K or 150 K by adding small amount of Bi₂O₃ or a mixture of B₂O₃ + CuO. Saturation magnetization and Curie temperature of YIG samples were almost independent of the addition of sintering additives. YIG specimens sintered at 1623 K with 1.5 wt% Bi₂O₃ and YIG sintered at 1523 K with 1.0 wt% of B₂O₃ + CuO mixture showed ferromagnetic resonance linewidth DH of 62 Oe and 58 Oe, respectively, compared with 65 Oe in pure YIG specimen sinterded at 1673 K for 2 hrs.