scholarly journals Impact of Praseodymia Additions and Firing Conditions on Structural and Electrical Transport Properties of 5 mol.% Yttria Partially Stabilized Zirconia (5YSZ)

2021 ◽  
Vol 11 (13) ◽  
pp. 5939
Author(s):  
Alejandro Natoli ◽  
Jorge R. Frade ◽  
Aleksandr Bamburov ◽  
Agnieszka Żurawska ◽  
Aleksey Yaremchenko
Keyword(s):  
Electrical Transport ◽  
Pyrochlore Phase ◽  
Nominal Composition ◽  
Ionic Conductors ◽  
Electrical Transport Properties ◽  
Praseodymium Oxide ◽  
Total Electrical Conductivity ◽  
Thermal Expansion Coefficients ◽  
Pyrochlore Type ◽  
P Type

Ceramics samples with the nominal composition [(ZrO2)0.95(Y2O3)0.05]1-x[PrOy]x and praseodymia contents of x = 0.05–0.15 were prepared by the direct firing of compacted 5YSZ + PrOy mixtures at 1450–1550 °C for 1–9 h and characterized for prospective applicability in reversible solid oxide cells. XRD and SEM/EDS analysis revealed that the dissolution of praseodymium oxide in 5YSZ occurs via the formation of pyrochlore-type Pr2Zr2O7 intermediate. Increasing PrOy additions results in a larger fraction of low-conducting pyrochlore phase and larger porosity, which limit the total electrical conductivity to 2.0–4.6 S/m at 900 °C and 0.28–0.68 S/m at 700 °C in air. A longer time and higher temperature of firing promotes the phase and microstructural homogenization of the ceramics but with comparatively low effect on density and conductivity. High-temperature processing leads to the prevailing 3+ oxidation state of praseodymium cations in fluorite and pyrochlore structures. The fraction of Pr4+ at 600–1000 °C in air is ≤2% and is nearly independent of temperature. 5YSZ ceramics with praseodymia additions remain predominantly oxygen ionic conductors, with p-type electronic contribution increasing with Pr content but not exceeding 2% for x = 0.15 at 700–900 °C. The average thermal expansion coefficients of prepared ceramics are in the range of 10.4–10.7 ppm/K.

scholarly journals Impact of Silica Additions on the Phase Composition and Electrical Transport Properties of Ruddlesden-Popper La2NiO4+δ Mixed Conducting Ceramics

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 82
Author(s):  
Kiryl Zakharchuk ◽  
Aleksandr Bamburov ◽  
Eugene N. Naumovich ◽  
Miguel A. Vieira ◽  
Aleksey A. Yaremchenko
Keyword(s):  
Electrical Transport ◽  
Solid Electrolytes ◽  
Lanthanum Oxide ◽  
Nominal Composition ◽  
Secondary Phases ◽  
Electrical Transport Properties ◽  
Total Electrical Conductivity ◽  
Type Lattice ◽  
Glycine Nitrate Combustion ◽  
Lanthanum Silicate

The present work explores the possibility of incorporation of silicon into the crystal structure of Ruddlesden-Popper La2NiO4+δ mixed conducting ceramics with the aim to improve the chemical compatibility with lanthanum silicate-based solid electrolytes. Ceramics with the nominal composition La2Ni1−ySiyO4+δ (y = 0, 0.02 and 0.05) were prepared by the glycine nitrate combustion technique and sintered at 1450 °C. While minor changes in the lattice parameters of the tetragonal K2NiF4-type lattice may suggest incorporation of a small fraction of Si into the Ni sublattice, combined XRD and SEM/EDS studies indicate that this fraction is very limited (≪2 at.%, if any). Instead, additions of silica result in segregation of apatite-type La10−xSi6O26+δ and La2O3 secondary phases as confirmed experimentally and supported by the static lattice simulations. Both total electrical conductivity and oxygen-ionic transport in La2NiO4+δ ceramics are suppressed by silica additions. The preferential reactivity of silica with lanthanum oxide opens a possibility to improve the compatibility between lanthanum silicate-based solid electrolytes and La2NiO4+δ-based electrodes by appropriate surface modifications. The promising potential of this approach is supported by preliminary tests of electrodes infiltrated with lanthanum oxide.

Electrical transport properties in nitrogen-doped p-type ZnO thin film

2006 ◽  
Vol 21 (12) ◽  
pp. 1522-1526 ◽  
Author(s):  
Z Y Xiao ◽  
Y C Liu ◽  
B H Li ◽  
J Y Zhang ◽  
D X Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Transport Properties ◽  
Electrical Transport ◽  
Zno Thin Film ◽  
Electrical Transport Properties ◽  
Nitrogen Doped ◽  
P Type

Electrical Transport Properties of Highly Aluminum Doped p-Type 4H-SiC

2016 ◽  
Vol 858 ◽  
pp. 249-252 ◽  
Author(s):  
Sylvie Contreras ◽  
Leszek Konczewicz ◽  
Pawel Kwasnicki ◽  
Roxana Arvinte ◽  
Hervé Peyre ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electrical Transport ◽  
Hole Concentration ◽  
Electrical Transport Properties ◽  
Capacitance Voltage ◽  
Experimental Values ◽  
Cv Measurements ◽  
P Type ◽  
Secondary Ion

In the range 80 K-900 K, we have investigated the electrical properties of heavily aluminum in-situ doped, 4H-SiC samples. The temperature dependence of the hole concentration and Hall mobility was analyzed in the model taking into account heavy and light holes. The modelisation parameters were compared with experimental values of Secondary Ion Mass Spectroscopy (SIMS) and Capacitance-Voltage (CV) measurements.

Electrical Transport Properties of the Pentatelluride Materials Hfte5 and Zrte5

1997 ◽  
Vol 478 ◽  
Author(s):  
T. M. Tritt ◽  
M. L. Wilson ◽  
R. L. Littleton ◽  
C. Feger ◽  
J. Kolis ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Electrical Transport ◽  
Entire Range ◽  
Room Temperature ◽  
Polycrystalline Material ◽  
Polycrystalline Materials ◽  
Electrical Transport Properties ◽  
Low Dimensional ◽  
P Type

AbstractWe have measured the resistivity and thermopower of single crystals as well as polycrystalline pressed powders of the low-dimensional pentatelluride materials: HfTe5 and ZrTe5. We have performed these measurements as a function of temperature between 5K and 320K. In the single crystals there is a peak in the resistivity for both materials at a peak temperature, Tp where Tp ≈ 80K for HfTe5 and Tp ≈ 145K for ZrTe5. Both materials exhibit a large p-type thermopower around room temperature which undergoes a change to n-type below the peak. This data is similar to behavior observed previously in these materials. We have also synthesized pressed powders of polycrystalline pentatelluride materials, HfTe5 and ZrTe5. We have measured the resistivity and thermopower of these polycrystalline materials as a function of temperature between 5K and 320K. For the polycrystalline material, the room temperature thermopower for each of these materials is relatively high, +95 μV/K and +65 μV/K for HfTe5 and ZrTe5 respectively. These values compare closely to thermopower values for single crystals of these materials. At 77 K, the thermopower is +55 μV/K for HfTe5 and +35 μV/K for ZrTe5. In fact, the thermopower for the polycrystals decreases monotonically with temperature to T ≈ 5K, thus exhibiting p-type behavior over the entire range of temperature. As expected, the resistivity for the polycrystals is higher than the single crystal material, with values of 430 mΩ-cm and 24 mΩ-cm for Hfre5 and ZrTe5 respectively, compared to single crystal values of 0.35 mΩ-cm (HfTe5) and 1.0 mΩ-cm (ZrTe5). We have found that the peak in the resistivity evident in both single crystal materials is absent in these polycrystalline materials. We will discuss these materials in relation to their potential as candidates for thermoelectric applications.

Electrical transport properties of Ag-doped p-type PbTe epitaxial thin films

1981 ◽  
Vol 68 (1) ◽  
pp. 227-232 ◽  
Author(s):  
A. L. Dawar ◽  
S. K. Paradkar ◽  
P. Kumar ◽  
O. P. Taneja ◽  
P. C. Mathur
Keyword(s):  
Thin Films ◽  
Transport Properties ◽  
Electrical Transport ◽  
Epitaxial Thin Films ◽  
Electrical Transport Properties ◽  
P Type
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