Improvements of Superconducting Properties on Bi-2212 Bulks by Element Doping

2014 ◽  
Vol 787 ◽  
pp. 448-453 ◽  
Author(s):  
Sheng Nan Zhang ◽  
Cheng Shan Li ◽  
Qing Bin Hao ◽  
Tian Ni Lu ◽  
Ping Xiang Zhang
Keyword(s):  
Carrier Concentration ◽  
Precipitation Process ◽  
Sintering Process ◽  
Al Content ◽  
Plasma Sintering ◽  
Element Doping ◽  
Spark Plasma ◽  
Co Precipitation ◽  
Precursor Powders ◽  
Pinning Properties

Bi-2212 bulks have been fabricated by spark plasma sintering technique with the Bi-2212 precursor powders synthesized by co-precipitation process. The Al2O3dopants were added into the precursor powders during the sintering process. The lattice parameters of Bi-2212 increased with Al content, suggesting that Al3+ions entering into the lattice as interstitial ions due to the small ion radii. The carrier concentration has been calculated with measured room temperature thermopower values. The change of carrier concentration can be attributed to the changes of both Al and oxygen contents in the lattice. Therefore, by Al doping the samples have been tuned into optimal doping region with maximum critical temperature of 86K. The appearance of Al interstitial ions in the lattice caused certain amount of point defects, which acted as pinning centers. Therefore the flux pinning properties have been enhanced in the bulks, and obvious improvements of critical current density for over 55% have been obtained at 4.2K self-field.

Tunable thermopower and thermal conductivity in Lu doped In2O3

RSC Advances ◽  
2014 ◽  
Vol 4 (60) ◽  
pp. 31926-31931 ◽  
Author(s):  
BeiBei Zhu ◽  
Ruoming Tian ◽  
Tianshu Zhang ◽  
Richard Donelson ◽  
Thiam Teck Tan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Hall Effect ◽  
Carrier Concentration ◽  
Spark Plasma Sintering ◽  
Valence State ◽  
Hall Effect Measurement ◽  
Precipitation Method ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Co Precipitation

Lu doped polycrystalline In2O3 compounds (x = 0, 0.025, 0.05, 0.10, 0.15) were synthesized by a co-precipitation method followed by the spark plasma sintering processing. Hall Effect measurement indicates that the carrier concentration was drastically decreased with doping, although Lu and In have the same valence state.

scholarly journals Carrier Modulation in Bi2Te3-Based Alloys via Interfacial Doping with Atomic Layer Deposition

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 572
Author(s):  
Sang-Soon Lim ◽  
Kwang-Chon Kim ◽  
Seunghyeok Lee ◽  
Hyung-Ho Park ◽  
Seung-Hyub Baek ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Carrier Concentration ◽  
Atomic Layer ◽  
Thermoelectric Performance ◽  
Fine Powders ◽  
Plasma Sintering ◽  
Novel Approach ◽  
Layer Deposition ◽  
Spark Plasma ◽  
Precursor Powders

The carrier concentration in Bi2Te3-based alloys is a decisive factor in determining their thermoelectric performance. Herein, we propose a novel approach to modulate the carrier concentration via the encapsulation of the alloy precursor powders. Atomic layer deposition (ALD) of ZnO and SnO2 was performed over the Bi2Te2.7Se0.3 powders. After spark plasma sintering at 500 °C for 20 min, the carrier concentration in the ZnO-coated samples decreased, while the carrier concentration in the SnO2-coated samples increased. This trend was more pronounced as the number of ALD cycles increased. This was attributed to the intermixing of the metal ions at the interface. Zn2+ substituted for Bi3+ at the interface acted as an acceptor, while Sn4+ substituted for Bi3+ acted as a donor. This indicates that the carrier concentration can be adjusted depending on the materials deposited with ALD. The use of fine powders changes the carrier concentration more strongly, because the quantity of material deposited increases with the effective surface area. Therefore, the proposed approach would provide opportunities to precisely optimize the carrier concentration for high thermoelectric performance.

Fabrication and Mechanical Properties of ultra fine WC-6wt.%Co by Spark Plasma Sintering Process

2011 ◽  
Vol 49 (01) ◽  
pp. 40-45 ◽  
Author(s):  
Hyun-Kuk Park ◽  
Seung-Min Lee ◽  
Hee-Jun Youn ◽  
Ki-Sang Bang ◽  
Ik-Hyun Oh
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Spark Plasma

scholarly journals Processing of MMC through conventional sintering and spark plasma sintering process: A review

2020 ◽  
Vol 988 ◽  
pp. 012092
Author(s):  
B Stalin ◽  
M Ravichandran ◽  
M Balasubramanian ◽  
C Anand Chairman ◽  
D Pritima ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Conventional Sintering ◽  
Spark Plasma

scholarly journals Shape Memory NiTi and NiTiCu Alloys Obtained by Spark Plasma Sintering Process

2015 ◽  
Vol 13 ◽  
pp. 83-90 ◽  
Author(s):  
Cristiana Diana Cristea ◽  
Magdalena Lungu ◽  
Alexander M. Balagurov ◽  
Virgil Marinescu ◽  
Otilia Culicov ◽  
...  
Keyword(s):  
Shape Memory ◽  
Intermetallic Compounds ◽  
Spark Plasma Sintering ◽  
Sintering Process ◽  
Transformation Behavior ◽  
Plasma Sintering ◽  
New Process ◽  
Shape Memory Properties ◽  
Spark Plasma ◽  
Niti Shape Memory Alloys

The addition of Cu to near equiatomic NiTi shape memory alloys (SMAs) can provide some modifications of their shape memory properties by affecting their transformation behavior. The same effect was obtained in the case of Ni3Ti2 and Ni4Ti3 precipitates presence in the microstructure of NiTi. Also the substitution of Cu to NiTi alloys increases the hardness of the materials. This paper presents the microstructural and mechanical investigations of NiTi and NiTiCu alloys obtained by spark plasma sintering (SPS) process that represents a great potential for researchers as a new process for the fabrication of intermetallic compounds.

scholarly journals Effects of Initial Punch-Die Clearance in Spark Plasma Sintering Process

2008 ◽  
Vol 49 (12) ◽  
pp. 2899-2906 ◽  
Author(s):  
Salvatore Grasso ◽  
Yoshio Sakka ◽  
Giovanni Maizza
Keyword(s):  
Spark Plasma Sintering ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Spark Plasma

Development of WC-Fe3Al Composites by Spark Plasma Sintering Process

2016 ◽  
Vol 881 ◽  
pp. 307-312
Author(s):  
Luis Antonio C. Ybarra ◽  
Afonso Chimanski ◽  
Sergio Gama ◽  
Ricardo A.G. da Silva ◽  
Izabel Fernanda Machado ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Zinc Stearate ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Al Composite ◽  
Spark Plasma ◽  
Short Time ◽  
Vibration Mill

Tungsten carbide (WC) based composites are usually produced with cobalt, but this binder has the inconvenience of shortage, unstable price and potential carcinogenicity. The objective of this study was to develop WC composite with intermetallic Fe3Al matrix. Powders of WC, iron and aluminum, with composition WC-10 wt% Fe3Al, and 0.5 wt% zinc stearate were milled in a vibration mill for 6 h and sintered in a SPS (spark plasma sintering) furnace at 1150 °C for 8 min under pressure of 30 MPa. Measured density and microstructure analysis showed that the composite had significant densification during the (low-temperature, short time) sintering, and X-ray diffraction analysis showed the formation of intermetallic Fe3Al. Analysis by Vickers indentation resulted in hardness of 11.2 GPa and fracture toughness of 24.6 MPa.m1/2, showing the feasibility of producing dense WC-Fe3Al composite with high mechanical properties using the SPS technique.

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