The effect of solute segregation to deformation twin boundaries on the electrical resistivity of a single-phase superalloy

2020 ◽  
Vol 186 ◽  
pp. 208-212
Author(s):  
Stoichko Antonov ◽  
Bernard Li ◽  
Baptiste Gault ◽  
Qing Tan
2013 ◽  
Vol 802 ◽  
pp. 218-222 ◽  
Author(s):  
Wanatchaporn Namhongsa ◽  
Tosawat Seetawan ◽  
Pennapa Muthitamongkol ◽  
Chanchana Thanachayanont

The polycrystalline of sodium cobalt oxide (Na0.5CoO2) was synthesized by solid state reaction method and sintering method. The microstructure was composed of powder size and crystal structure. The Seebeck coefficient and electrical resistivity are measured. We found that the concentration of sodium ions sandwiched between two neighboring CoO2layers played a crucial role in transport properties. The results showed small particle size, single phase and orthorhombic structure. The Seebeck coefficient of Na0.5CoO2increased as the temperature increased. The electrical resistivity was decreased as temperature decreased from the range 300-500 K.


2009 ◽  
Vol 92 (10) ◽  
pp. 2425-2428 ◽  
Author(s):  
Prita Pant Sarangi ◽  
Sampat Raj Vadera ◽  
Manoj Kumar Patra ◽  
Chandra Prakash ◽  
Narendra Nath Ghosh

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1212 ◽  
Author(s):  
Changchun Wang ◽  
Lele Song ◽  
Yupeng Xie

Single-phase tungsten diboride (WB2) was synthesized at high pressure and high temperature. The different grain sizes ranging from 300 nm to 3 µm were successfully obtained in WB2 by controlling the experimental conditions. The effects of grain size on hardness and resistivity properties were investigated. The Vickers hardness of WB2 was modulated with grain size. The maximum asymptotic Vickers hardness is 25.5 GPa for WB2 with a grain size of 300 nm which is a 10% increase compared to WB2 with a grain size of 3 µm. The optimal electrical resistivity of WB2 was 10−7 Ωm with the biggest grain size of 3 µm, which is ascribed to low grain boundary density. The superior properties of hardness and electrical resistivity demonstrate that WB2 should be a new functional hard material replacing WC which is widely used in industrial production.


2004 ◽  
Vol 819 ◽  
Author(s):  
Randall S. Hay

AbstractMonazite (LaPO4) was indented at room temperature. Deformation twin boundaries and stacking faults were characterized by high resolution transmission electron microscopy. Kinked deformation twins were also characterized and analyzed. Three types of stacking faults associated with climb-dissociated partial dislocations were observed. Two were found on twin boundaries, and a third in the lattice. Formation mechanisms are discussed. The superimposition of stacking faults along twin boundaries during deformation twinning and the glide of climb-dissociated partial dislocations allowed by stacking fault migration are discussed. The possible relationship between the formation mechanisms for these defects and the low- temperature recrystallization and self-annealing of defects in monazite is considered.


2016 ◽  
Vol 701 ◽  
pp. 220-224
Author(s):  
Milan Chandra Barma ◽  
Bui Duc Long ◽  
Mohd Faizul Mohd Sabri ◽  
Ramesh Singh ◽  
Suhana Mohd Said ◽  
...  

Cu3.21Bi4.79S9 was synthesized from Cu, Bi and S element powders using mechanical alloying method. The formation of Cu3.21Bi4.79S9 was identified using XRD and the changes of morphologies of the mixtures of Cu, Bi, and S powders during milling were observed using table top SEM. The milled powders were sintered using Hot-isostatic pressing at 230°C with a pressure of 50 MPa. Electrical resistivity and Seebeck coefficient of sintered samples were measured using ZEM-3 (Electrical resistivity and Seebeck Coefficient measuring System). Cu3.21Bi4.79S9 and some secondary phases were found in the 5h milled powder but single phase Cu3.21Bi4.79S9 was only obtained after milling for 15 h. A minimum electrical resistivity of sintered Cu3.21Bi4.79S9 sample was found to be 0.66 Ω.m at 170°C. We observed that a n- to p-type conversion at temperature of around 75 °C. However, a maximum n-type Seebeck coefficient of Cu3.21Bi4.79S9 was of -214 μV/K at 45 °C. The Seebeck coefficient decreases with increasing temperature and it reaches zero value at around 75 °C and then p-type Seebeck coefficient increases with increasing the temperature. The maximum p-type Seebeck coefficient was observed of 202 μV/K at 170°C.


2015 ◽  
Vol 107 (9) ◽  
pp. 091901 ◽  
Author(s):  
S. B. Jin ◽  
K. Zhang ◽  
R. Bjørge ◽  
N. R. Tao ◽  
K. Marthinsen ◽  
...  

2002 ◽  
Vol 16 (25) ◽  
pp. 943-953 ◽  
Author(s):  
H. KHOSROABADI ◽  
V. DAADMEHR ◽  
M. AKHAVAN

We prepared single-phase polycrystalline Gd 1 - x Pr x Ba 2 Cu 3 O 7 - δ samples with x = 0, 0.10, 0.15, and 0.20. The deoxygenation process of these samples was performed by an annealing method. Electrical resistivity measurements revealed depression of the transition temperature with the increase of x and δ. We calculated the hole concentration in the CuO 2 plane for different values of x and δ. A linear dependence of transition temperature and hole concentration in the CuO 2 plane was found as a function of 2δ + x. It is proposed that a combination of the localization and filling of holes should be considered as the effective mechanisms for the appearance of the Pr anomaly in HTSCs.


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