scholarly journals Towards a detailed comprehension of the inertisation processes of amphibole asbestos: in situ high-temperature behaviour of fibrous tremolite

2020 ◽  
pp. 1-37
Author(s):  
Paolo Ballirano ◽  
Alessandro Pacella
Keyword(s):  
High Temperature ◽  
Temperature Behaviour ◽  
Amphibole Asbestos

scholarly journals In situ high-temperature behaviour of fluor-elbaite: breakdown conditions and products

2021 ◽  
Vol 48 (6) ◽  
Author(s):  
Beatrice Celata ◽  
Paolo Ballirano ◽  
Giovanni B. Andreozzi ◽  
Ferdinando Bosi
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Structural Parameters ◽  
Unit Cell ◽  
Temperature Behaviour ◽  
Unit Cell Parameters ◽  
Thermally Induced ◽  
X Ray ◽  
Cell Parameters

AbstractThe thermal behaviour of a fluor-elbaite from Minas Gerais (Brazil) was investigated at room pressure through in situ high-temperature X-ray powder diffraction (HT-XRPD), until the breakdown conditions were reached. The variations of fluor-elbaite structural parameters (unit-cell parameters and mean bond distances) were monitored together with site occupancies, and two main internal reactions were identified: the thermally-induced Fe oxidation process counterbalanced by (OH)– deprotonation, which starts at 500 °C (773 K), followed by a partial intracrystalline Fe–Al exchange between the octahedrally-coordinated Y and Z sites. The fluor-elbaite breakdown reaction occurs between 850 °C (1123 K) and 900 °C (1173 K). The breakdown products were identified at room temperature by XRPD and the breakdown reaction can be described by the following reaction: tourmaline → B-bearing mullite + hematite + spinel + B-poor (Na, Li, H2O)-bearing glass. Boromullite itself was not observed in the final heating products, and the B-bearing mullite from the breakdown reaction exhibited unit-cell parameters a = 7.5382(2) Å, b = 7.6749(2) Å, c = 2.8385(1) Å, V = 164.22(1) Å3 (space group Pbam) consistent with an approximate Al8.5B1.5Si2O19 composition.

scholarly journals Structure and reactivity with oxygen of Pr2NiO4+δ: an in situ synchrotron X-ray powder diffraction study

2016 ◽  
Vol 45 (7) ◽  
pp. 3024-3033 ◽  
Author(s):  
Thibault Broux ◽  
Carmelo Prestipino ◽  
Mona Bahout ◽  
Serge Paofai ◽  
Erik Elkaïm ◽  
...  
Keyword(s):  
High Temperature ◽  
Cathode Material ◽  
Partial Pressure ◽  
Diffraction Study ◽  
Powder Diffraction ◽  
Temperature Behaviour ◽  
Sofc Cathode ◽  
X Ray

The high temperature behaviour of the SOFC cathode material Pr2NiO4.22 was revisited in situ as function of O2 partial pressure.

The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

1990 ◽  
Vol 48 (4) ◽  
pp. 664-665
Author(s):  
N. Rozhanski ◽  
A. Barg
Keyword(s):  
High Temperature ◽  
Crystallization Temperature ◽  
Diffusion Barriers ◽  
Sio2 Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Plan View ◽  
Temperature Range ◽  
Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

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