Lee, Hang-Won Park, Jeong-Hyun Nahm, Sahn Kim, Dong-Wan Park, Jae-Gwan 2024-01-20T20:03:08Z 2024-01-20T20:03:08Z 2021-09-04 2010-01 0025-5408 https://pubs.kist.re.kr/handle/201004/131835 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 degrees 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 degrees C for 2 h possessed the following excellent microwave dielectric properties: a quality factor (Qxf) of 49,000 GHz, relative dielectric constant (epsilon(r)) of 19.5, and temperature coefficient of resonant frequency (tau(f)) of 1 ppm/degrees C. The ferroelastic phase transformation was also investigated using in situ X-ray diffraction (XRD) to explain the variation of tau(f) in low-temperature sintered LaNbO4 as a function of CuO content. (C) 2009 Elsevier Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD RARE-EARTH ORTHONIOBATE BEHAVIOR Low-temperature sintering of temperature-stable LaNbO4 microwave dielectric ceramics Article 10.1016/j.materresbull.2009.09.008 1 MATERIALS RESEARCH BULLETIN, v.45, no.1, pp.21 - 24 MATERIALS RESEARCH BULLETIN 45 1 21 24 scie scopus 000272579700005 2-s2.0-70449127059 Materials Science, Multidisciplinary Materials Science Article RARE-EARTH ORTHONIOBATE BEHAVIOR Ceramics Oxides Electron microscopy Dielectric properties Microstructure