کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1528832 1511982 2014 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Dielectric permittivity of some novel copper/cobalt and rare-earth metal tungstates
ترجمه فارسی عنوان
دینامیکی دی اکسید کربن مس و کبالت و تنگستات های خاکی کمیاب
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد مواد الکترونیکی، نوری و مغناطیسی
چکیده انگلیسی


• New copper tungstates including samarium and europium were synthesized.
• Dielectric constant strongly depends on the ions having the unpaired electrons.
• Temperature and frequency strongly influence the permittivity and the lossiness.

Polycrystalline samples of new copper and samarium tungstates (Cu3Sm2W4O18 and CuSm2W2O10) and cobalt and europium tungstate (CoEu4W3O16) have been successfully synthesized by the solid state reaction of d-electron metal tungstates MWO4 (M = Cu, Co) with corresponding rare-earth metal tungstate RE2WO6 (RE = Sm and Eu). Broadband dielectric spectroscopy provides experimental evidence that in tungstates under study both relative dielectric permittivity (ɛr) and loss tangent (tan δ) strongly depend on the temperature and frequencies. Maximal relative permittivity value ɛr = 42 for CuSm2W2O10, ɛr = 30 for Cu3Sm2W4O18, and ɛr = 63,000 for CoEu4W3O16 at low frequency (ν = 0.1 Hz) and at 373 K indicates that only these ions which have the large number of unpaired and unscreened electrons on the unfilled shells are responsible for the colossal dielectric effect.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: B - Volume 184, May–June 2014, Pages 14–17
نویسندگان
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