Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: gadolinium doped cerium oxide

Sortuj według:

Ogranicz wyniki do:

Preparation and microstructural characterization of Si(100) Ce1−x Gd x O2−δ thin films prepared by pulsed laser deposition technique

Nagaraju P, Vijayakumar Y, Phase D M, Reddy V R

Materials Science Poland

2014

Vol. 32, No. 4

541--546

Microstructural properties of Ce1−xGdxO2−δ (x = 0 to 0.3) thin films prepared by pulsed laser deposition technique were studied. The thin films were deposited on Si(100) substrate at a substrate temperature of 973 K at the oxygen partial pressure of 0.2 Pa using KrF excimer laser with energy of 220 mJ. The prepared thin films were characterized by X-ray diffraction, Raman spectroscopy and atomic force microscopy. X-ray diffraction analysis confirmed the polycrystalline nature of the thin films. Crystallite size, strain and dislocation density were calculated. The Raman studies revealed the formation of Ce–O with the systematic variation of peak intensity and full width half maxima depending on concentration of gadolinium dopant. The thickness of the films was estimated using Talystep profiler. The surface roughness was estiamted based on AFM.

Transport properties of nanocrystalline and microcrystalline Gd-doped ceria

Baldinozzi G., Dolle M., Kusiński J., Petot C., Petot-Ervas G.

Inżynieria Materiałowa

2010

Vol. 31, nr 3

483-486

Electrical conductivity measurements of Gd-doped ceria polycrystals, sintered from different sources of submicronic powder, have allowed us to illustrate the influence of size scale on the ionic conductivity. In samples doped with 10 moles % Gd2O3. The ionic conductivity passes through a maximum for grain sizes included between 200 and 500 nm. Furthermore, for the nanocrystalline samples an enhancement of the ionic conductivity is observed when the amount of dopant increases.These results were analyzed according to XPS characterizations performed on polycrystal fracture surfaces. These analysis show a grain size dependent gadolinium segregation at the periphery of the grains, which decreases with grain size, but which depends also of both densification conditions and starting powders. It follows from this set of results that the maximum of ionic conductivity occurs for a mean enrichment at the periphery of the grains close to Gd/ Ce = 0.9.

Polikrystaliczne probki CeO2 domieszkowane gadolinem spiekano z różnego rodzaju mieszanin nano- i mikroproszkow. Wyniki badań uzyskanych na próbkach zawierających 10% mol. Gd2O3 pokazują, że przewodnictwo jonowe osiąga maksimum w zakresie wielkości ziarna pomiędzy 200 do 300 nm. Ponadto wykazano, że w nanokrystalicznych próbkach wzrost przewodnictwa jonowego następuje wraz ze wzrostem zawartości domieszki, podczas gdy dla materiału gruboziarnistego przewodnictwo jonowe osiąga maksimum przy 10% mol. Gd2O3. Wyjaśniono to, jako efekt wpływu wielkości ziarna proszku na segregację Gd do zewnętrznych stref ziaren, co potwierdzono badaniami za pomocą techniki XPS na przełomach próbek.