Abstract
We demonstrate the correlation between sintering behavior and microstructural observations in low-temperature sintered, LaNbO4 microwave ceramics. Small CuO additions to LaNbO4 significantly lowered the sintering temperature from 1250 to 950 °C. To elucidate the sintering mechanism, the internal microstructure of the sample manipulated by a focused ion beam (FIB) was investigated using transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS). LaNbO4 with 3 wt% CuO sintered at 950 °C for 2 h possessed the following excellent microwave dielectric properties: a quality factor (Qxf) of 49,000 GHz, relative dielectric constant (εr) of 19.5, and temperature coefficient of resonant frequency (τf) of 1 ppm/°C. The ferroelastic phase transformation was also investigated using in situ X-ray diffraction (XRD) to explain the variation of τf in low-temperature sintered LaNbO4 as a function of CuO content.
Original language | English |
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Pages (from-to) | 21-24 |
Number of pages | 4 |
Journal | Materials Research Bulletin |
Volume | 45 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2010 Jan |
Keywords
- A. Ceramics
- A. Oxides
- C. Electron microscopy
- D. Dielectric properties
- D. Microstructure
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering