کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1491200 992345 2009 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Phase transitions, structure and ion conductivity of zirconium hydrogen phosphates, H1±XZr2−XMX(PO4)3·H2O (M = Nb, Y)
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Phase transitions, structure and ion conductivity of zirconium hydrogen phosphates, H1±XZr2−XMX(PO4)3·H2O (M = Nb, Y)
چکیده انگلیسی

Structure transformations and proton conductivity of hydrogen zirconium phosphates with the NASICON structure, H1±XZr2−XMX(PO4)3·H2O (X = 0, 0.02 and 0.1, M = Nb, Y), were studied by X-ray powder diffraction, calorimetry, IR- and impedance spectroscopy. Substitution of zirconium by niobium leads to decrease of the lattice parameters, while yttrium doping leads to their increase. H0.9Zr1.9Nb0.1(PO4)3 structure was determined at 493 and 733 K. This phase crystallizes in rhombohedral space group R3¯c with lattice parameters a = 8.8564(5) Å, c = 22.700(1) Å at 493 K and a = 8.8470(2) Å, c = 22.7141(9) Å at 733 K. The a parameter and lattice volume were found to decrease with temperature increasing. Structure transformations upon heating are caused mainly by the decrease of the M1 site and C cavities. Ion conductivity of obtained materials was found to increase in humid atmosphere. Activation energies of conductivity were calculated. Rhombohedral–triclinic phase transition found by X-ray powder diffraction was proved by calorimetry data. According to XRD and IR spectroscopy data hydrogen bond in HZr2(PO4)3 was found to be weaker than in hydrated material.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Research Bulletin - Volume 44, Issue 7, 1 July 2009, Pages 1608–1612
نویسندگان
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