Premium
Crystal Structure and Microwave Dielectric Properties of LaLuO 3 Ceramics
Author(s) -
Varghese Jobin,
Joseph Tony,
Sebastian Mailadil Thomas,
ReevesMcLaren Nik,
Feteira Antonio
Publication year - 2010
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2010.03930.x
Subject(s) - orthorhombic crystal system , rietveld refinement , raman spectroscopy , crystal structure , materials science , temperature coefficient , relative permittivity , ceramic , microwave , dielectric , crystal (programming language) , analytical chemistry (journal) , space group , crystallography , diffraction , x ray crystallography , permittivity , mineralogy , chemistry , optics , optoelectronics , physics , metallurgy , composite material , programming language , chromatography , quantum mechanics , computer science
Dense LaLuO 3 ceramics were prepared by the conventional solid‐state reaction route. Their room‐temperature (RT) crystal structure and microwave (MW) dielectric properties were investigated. Rietveld refinements performed on X‐ray diffraction data show the RT crystal symmetry to be best described by the centrosymmetric orthorhombic Pnma space group [ a =6.01888 (9) Å, b =8.37489 (12) Å, and c =5.81841 (8) Å, Z =4]. This space group assignment was further corroborated by Raman spectroscopy analysis. At RT and MW frequencies, LaLuO 3 ceramics sintered at 1525°C/4 h exhibit a relative permittivity, ɛ r =22.4, a quality factor, Q u × f =14 400 GHz (at 5.14 GHz), and temperature coefficient of resonant frequency, τ f =−7.5 ppm/°C. ɛ r corrected for porosity was calculated as 23.9.