Nickel Nitrate and Molybdenum Oxide as a Yttria-Stabilized Zirconia Synergistic Sintering Aid

Hunt, Clay; Driscoll, David R.; Weisenstein, Adam; Sofie, Stephen W.

doi:10.1002/9781119323303.ch27

Cited by 2 publications

(6 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure 3c, stacks of perpendicularly grown plates were deposited on the substrate and the Raman spectra of these species verified the formation of various lower-valence-state Mo oxides 34,35 (see Figure S3d). Furthermore, the XRD data (Figure 3d) for the black-colored powder remaining in the boat indicated that most of the MoO 25,26 In Stage III (above 780 °C), the sulfur-induced transition to MoS 2 proceeds from the edges of the substrate to the center, as shown in Figure 2, demonstrating the possible dependence of this transition on the amount of sulfur supplied. Therefore, an increase in the number of MoS 2 atomic layers is expected upon increasing the sulfurization time in Stage III.…”

Section: ■ Results and Discussionmentioning

confidence: 95%

“…With progress of the CVD process, melting of the sulfur powder was initiated (at a CVD temperature over 680 °C, which corresponds to a temperature exceeding 105 °C at the site of the sulfur-containing boat), and the reaction zone quickly changed to a highly reducing atmosphere under a sufficient sulfur-vapor supply. Under these highly reducing conditions, it was expected that most of the deposited MoO 3– x would be quickly transformed to a nonvolatile compound such as MoO 2 − before resubliming, given that the ramping rate (>50 °C min –1 ) was much higher than that used for conventional CVD processes (generally, <20 °C min –1 ). ,− …”

Section: Results and Discussionmentioning

confidence: 99%

“…This indicates that the vaporized sulfur largely suppressed sublimation of MoO 3 by quickly transforming MoO 3 to nonvolatile species when the temperature approached 800 °C. MoO 2 is thought to be the nonvolatile compound formed during the TG/DTA measurement based on its formation temperature (775 °C in the case of sulfur-induced reduction of MoO 3 ) and sublimation temperature (1100 °C). , Consequently, it was expected that the nonvolatile intermediate MoO 2 formed during the CVD process would be sulfurized during the prolonged process at high temperature.…”

Section: Results and Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Synthesis of Vertical MoO₂/MoS₂ Core–Shell Structures on an Amorphous Substrate via Chemical Vapor Deposition

et al. 2017

View full text Add to dashboard Cite

Vertical MoO 2 /MoS 2 core−shell structures were synthesized on an amorphous surface (SiO 2 ) by chemical vapor deposition at a high heating rate using a configuration in which the vapor phase was confined. The confined reaction configuration was achieved by partially covering the MoO 3 -containing boat with a substrate, which allowed rapid buildup of the partially reduced MoO 3−x crystals in an early stage (below 680 °C). Rapid temperature ramping to 780 °C enabled spontaneous transition of the reaction environment from sulfur-poor to sulfur-rich, which induced a sequential phase transition from MoO 3−x to intermediate MoO 2 and finally to MoO 2 /MoS 2 core−shell structures. The orthorhombic crystal structure of MoO 3−x contributed to the formation of vertical crystals on the amorphous substrate, whereas the nonvolatility of the subsequently formed MoO 2 enabled layer-by-layer sulfurization to form MoS 2 on the oxide surface with minimal resublimation loss of MoO 2 . By adjustment of the sulfurization temperature and time, excellent control over the thickness of the MoS 2 shell was achieved through the proposed synthesis method.

show abstract

Section: ■ Results and Discussionmentioning

confidence: 95%

Section: Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of Vertical MoO₂/MoS₂ Core–Shell Structures on an Amorphous Substrate via Chemical Vapor Deposition

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Table 1. Green density, final sintered density, and maximum sintering rate; density measurements are relative to 5.9 g/cm 3 and given as a percent of theoretical density, and sintering rate as change in percent relative density per minute (%/min) (Adapted from [32]). The resistance term of this ubiquitous law is given as exp(−Q/RT).…”

Section: Resultsmentioning

confidence: 99%

“…(D) Ni(NO 3 ) 2 infiltrated 8YSZ with 10 mol.% MoO 2, where all samples were sintered up to and held at 1200 • C for one hour. From[32] with copyright permission.…”

mentioning

confidence: 99%

Molybdenum Oxide and Nickel Nitrate as Cooperative Sintering Aids for Yttria-Stabilized Zirconia

et al. 2020

Self Cite

View full text Add to dashboard Cite

The entirely accidental observation of increased sintering performance of nickel-infiltrated yttria-stabilized zirconia (8YSZ) in a molybdenum and oxygen rich atmosphere was explored. Molybdenum and nickel were found to be synergistic sintering aids for 8YSZ. However, sintering had to take place in an atmosphere of flowing oxygen. Samples sintered in air consistently burst. The sintering performance, microstructure, and crystal structure of 8YSZ with additions of both Mo and Ni together are compared to the sintering performance, microstructure, and crystal structure of pure 8YSZ, 8YSZ with only Ni added as a sintering aid, and 8YSZ with only Mo added as a sintering aid. Enhanced densification and grain growth is observed in the Mo–Ni 8YSZ samples when compared to all other sintering samples. Order of magnitude sintering rate increases are observed in the Mo–Ni 8YSZ over that of pure 8YSZ. With a maximum sintering temperature of 1200 °C and a one-hour dwell, sintered densities of 85% theoretical density (5.02 g⁄cm3) are achieved with the Mo–Ni samples: a 57% increase in density over pure 8YSZ sintered with the same sintering profile. EIS results suggest conductivity may not be negatively impacted by the use of these two sintering aids at temperatures above 750 °C. Finally, the spontaneous generation of nickel-molybdenum nano-rods was observed on the 5, and 10 mol.% Mo–Ni infiltrated 8YSZ samples after being left under vacuum in a scanning electron microscope chamber, suggesting evaporation of a possible nickel–molybdenum compound from the sample fracture surfaces.

show abstract

Nickel Nitrate and Molybdenum Oxide as a Yttria-Stabilized Zirconia Synergistic Sintering Aid

Cited by 2 publications

References 27 publications

Synthesis of Vertical MoO₂/MoS₂ Core–Shell Structures on an Amorphous Substrate via Chemical Vapor Deposition

Synthesis of Vertical MoO₂/MoS₂ Core–Shell Structures on an Amorphous Substrate via Chemical Vapor Deposition

Molybdenum Oxide and Nickel Nitrate as Cooperative Sintering Aids for Yttria-Stabilized Zirconia

Contact Info

Product

Resources

About

Nickel Nitrate and Molybdenum Oxide as a Yttria-Stabilized Zirconia Synergistic Sintering Aid

Cited by 2 publications

References 27 publications

Synthesis of Vertical MoO2/MoS2 Core–Shell Structures on an Amorphous Substrate via Chemical Vapor Deposition

Synthesis of Vertical MoO2/MoS2 Core–Shell Structures on an Amorphous Substrate via Chemical Vapor Deposition

Molybdenum Oxide and Nickel Nitrate as Cooperative Sintering Aids for Yttria-Stabilized Zirconia

Contact Info

Product

Resources

About

Synthesis of Vertical MoO₂/MoS₂ Core–Shell Structures on an Amorphous Substrate via Chemical Vapor Deposition

Synthesis of Vertical MoO₂/MoS₂ Core–Shell Structures on an Amorphous Substrate via Chemical Vapor Deposition