Solid-state Reaction Study on Physically and Tribochemically Prepared BaC2O4-SnC2O4 Mixtures

2012 ◽  
Vol 67 (7) ◽  
pp. 667-672 ◽  
Author(s):  
Vittorio Berbenni ◽  
Chiara Milanese ◽  
Giovanna Bruni ◽  
Alessandro Girella ◽  
Amedeo Marini
Keyword(s):  
Differential Scanning Calorimetry ◽  
Solid State ◽  
Mechanical Activation ◽  
Solid State Reaction ◽  
Differential Scanning Calorimetric ◽  
Temperature Differential ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Reaction Study ◽  
Modulated Temperature

The synthesis of barium metastannate, BaSnO3, by heating mixtures of metal oxalates, either physically mixed or subjected to a phase of mechanical activation, up to temperatures in the range 750- 1200 °C has been studied. Simultaneous thermogravimetric-differential scanning calorimetric (TGDSC) analyses and powder X-ray diffractometry have been applied to check the advancement of the reactions. BaSnO3, though slightly contaminated by BaCO3, can be obtained by heating the activated mixture up to T ≥ 1000 °C while heating a sample of a physical mixture at temperature as high as 1200 °C resulted in a mixture of BaSnO3, SnO2 and Ba2SnO4. The heat capacities of BaSnO3 samples prepared at temperatures between 1000 and 1200 °C have been measured by modulated temperature differential scanning calorimetry (MTDSC) in the temperature range 50-400 °C.

PHASE TRANSFORMATIONS DURING HEATING OF AMORPHOUS/NANOCRYSTALLINE Ni–Ti POWDERS

2010 ◽  
Vol 24 (09) ◽  
pp. 1137-1140 ◽  
Author(s):  
M. M. VERDIAN ◽  
M. SALEHI ◽  
K. RAEISSI
Keyword(s):  
Differential Scanning Calorimetry ◽  
Solid State ◽  
Phase Transformations ◽  
Low Energy ◽  
Heating Process ◽  
Study Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Niti Phase

Amorphous/nanocrystalline 50 Ni –50 Ti powders were synthesized from elemental Ti and Ni powders by solid state synthesis utilizing low energy mechanical alloying with times up to 100 h. The produced powders were investigated by X-ray diffraction and differential scanning calorimetry to study phase transformations that occurred during heating in the calorimeter. It was found that at the first stage of the heating process, a disordered NiTi phase was formed at temperature of about 400°C. Further investigations indicated that this phase transformed into the Ni 3 Ti and Ti 2 Ni intermetallic compounds after heating at a temperature of about 800°C.

Mechanothermal Synthesis of SrSnO3

2014 ◽  
Vol 69 (3) ◽  
pp. 313-320 ◽  
Author(s):  
Vittorio Berbenni ◽  
Chiara Milanese ◽  
Giovanna Bruni ◽  
Alessandro Girella ◽  
Amedeo Marini
Keyword(s):  
Solid State ◽  
Mass Loss ◽  
Mechanical Activation ◽  
Solid State Reaction ◽  
Thermal Activation ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Experiments ◽  
Physical Mixtures

The synthesis of strontium metastannate (SrSnO3) has been performed by coupling mechanical activation with thermal activation of SnC2O4-SrCO3 mixtures. The solid-state reaction has been studied by TG-DSC analysis and powder X-ray diffraction. By annealing experiments performed on physical mixtures (no mechanical activation) it has been assessed that the formation of SrSnO3 occurs through the intermediate Sr2SnO4 and is complete only after annealing at 1400 °C. By performing the annealing experiments on activated mixtures it has been established that the formation of SrSnO3 takes place directly at temperatures between 800 and 1000 °C. The SrSnO3 samples obtained at 800 and 900 °C show, by TG analysis, mass loss processes that suggest that SrSnO3 obtained at these temperatures absorbs H2O and CO2 from the air so that its use as gas sensor can be envisaged. This is no longer true for the sample obtained at 1000 °C or above

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