No.2（1999）27.Effects of γirradiation on the electrical properties of microwave dielectric ceramics

Ryouichi FUKUCHI, Takashi SEKIGUCHI, Masaru KIZAKI, Kinya HASHIMOTO, Katsumi YAMAMOTO and Masakuni KOSUGI

Irradiation effects of γ-rays on the microwave dielectric properties (relative dielectric constant ε' ,Dielectric loss tanδ) and dielectric breakdown strength (AC and DC voltage) for three different types of microwave dielectric ceramics (alumina,aluminium nitride, zirconium tin titanate) were studied by comparison with some non-irradiated ceramic samples. The samples were irradiated with γ-rays at room temperature using a ⁶⁰Co source. After irradiation, the dielectric properties of the samples were measured by means of reflection measurement techniques using a network analyzer in a microwave frequency range from 0.1GHz to 20GHz at room temperature.No changes were recognized in the dielectric properties of the samples irradiated with γ-rays at a dose range from 300kGy to 5000kGy. For dielectric breakdown strength of the irradiated samples, it was found that only DC breakdown strength of the irradiated aluminium nitride decreased from 94kV/mm to 39kV/mm at a dose of 1kGy and no changes were observed in the other irradiated samples.

Keywords
Microwave dielectric ceramics, γ-ray, Irradiation effects, Alumina, Aluminium nitride, Zirconium tin titanate, Dielectric property, Dielectric breakdown

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