Mechanical alloying studies in the Γ(Fe3Zn10) and Γ1(Fe5Zn21) single and mixed phase compositions

1998 ◽  
Vol 13 (5) ◽  
pp. 1177-1185 ◽  
Author(s):  
Aszetta Jordan ◽  
Zhentong Liu ◽  
Oswald N. C. Uwakweh
Keyword(s):  
Differential Scanning Calorimetry ◽  
Stable Equilibrium ◽  
Mixed Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Crystalline Materials ◽  
X Ray ◽  
Dsc Measurements ◽  
Fe Sites

Homogeneous or uniform crystalline materials are obtained following the ball milling of pure elemental powders of Fe and Zn in proportions to yield single phases Γ(Fe3Zn10), Γ1(Fe5Zn21), and Γ + Γ1 mixed phase (Fe25Zn75). Differential scanning calorimetry (DSC) measurements of the as-milled materials show characteristic stages in the temperature range of 50–600 °C prior to establishing stable equilibrium. The activation energies determined from kinetic analyses range from 49 to 189 kJ/mole in these materials. A characteristic stage at 130 °C marking the distinct evolution of the Γ and Γ1 phases from the intermediate or mixed phase composition is identified from XRD measurements. The identification of a unique Fe site with a quadrupole splitting (QS) of 1.5 mm/s in corroboration with x-ray diffraction (XRD) shows that this stage marks the onset of an in situ transformation prior to the distinct evolution of the homogeneous phases. The Mössbauer effect measurement of the as-milled materials are resolved in terms of four unique Fe sites with QS of 1.1, 0.241, 0.073, and 0.0772 mm/s.

Crystal formation in vanadium-doped zirconia ceramics

CrystEngComm ◽  
2018 ◽  
Vol 20 (22) ◽  
pp. 3105-3116 ◽  
Author(s):  
Roman Svoboda ◽  
Roman Bulánek ◽  
Dušan Galusek ◽  
Roghayeh Hadidimasouleh ◽  
Yadolah Ganjkhanlou
Keyword(s):  
Differential Scanning Calorimetry ◽  
Diffraction Analysis ◽  
Crystal Formation ◽  
X Ray Diffraction ◽  
Zirconia Ceramics ◽  
Scanning Calorimetry ◽  
X Ray

Differential scanning calorimetry and in situ X-ray diffraction analysis were used to study the products and mechanism of crystal formation in VOx–ZrO2 ceramics.

A Model for Formation and Consumption of Transient Phase

2011 ◽  
Vol 172-174 ◽  
pp. 646-651 ◽  
Author(s):  
Gamra Tellouche ◽  
Khalid Hoummada ◽  
Dominique Mangelinck ◽  
Ivan Blum
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Formation ◽  
Transient Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Proposed Model ◽  
Transient Phases ◽  
Kinetics Of

The phase formation sequence of Ni silicide for different thicknesses is studied by in situ X ray diffraction and differential scanning calorimetry measurements. The formation of a transient phase is observed during the formation of δ-Ni2Si; transient phases grow and disappear during the growth of another phase. A possible mechanism is proposed for the transient phase formation and consumption. It is applied to the growth and consumption of θ-Ni2Si. A good accordance is found between the proposed model and in situ measurement of the kinetics of phase formation obtained by x-ray diffraction and differential scanning calorimetry for higher thickness.

In-Situ Characterisation of Precipitation in AI-Cu thin films

1999 ◽  
Vol 562 ◽  
Author(s):  
J. P. Lokker ◽  
A. J. Bottger ◽  
G. C. A. M. Janssen ◽  
S. Radelaar
Keyword(s):  
Thin Films ◽  
Differential Scanning Calorimetry ◽  
Bulk Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Enthalpy Changes ◽  
Thin Foils ◽  
Lower Temperature

ABSTRACTThe precipitate formation occurring in Al-Cu thin foils with copper concentrations of either 1.15 at.% or 0.3 at.%, has been studied. In-situ X-ray diffraction analysis and differential scanning calorimetry are applied to determine the phases formed and the enthalpy changes in the same samples. Both X-ray diffraction and differential scanning calorimetry indicate that the precipitation behaviour of thin films (about 500 nm thickness) differs significantly from that of bulk material. In the films studied the precipitation of Al2Cu occurs at a much lower temperature than expected on the basis of the (bulk) phase diagram. Moreover, no intermediate phases are observed prior to Al2Cu precipitation. Also the amount of Cu in solid solution (0.20 at%Cu) observed by electron-probe micro-analysis after slowly cooling from 500°C to room temperature, exceeds the solubility of bulk Al-Cu.

scholarly journals X-Ray Diffraction and Differential Scanning Calorimetry of BaTiO3/ Polyvinyl Chloride Nanocomposites

2015 ◽  
Vol 1 (10) ◽  
pp. 359
Author(s):  
Mohamed Yousef Farag El Zayat
Keyword(s):  
Differential Scanning Calorimetry ◽  
Polyvinyl Chloride ◽  
Structural Changes ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
The Core ◽  
Dsc Measurements ◽  
Scherrer Formula ◽  
Composite Samples

AbstractAiming to improve the inferior properties of polyvinyl chloride polymer, (BaTiO3)x(PVC)100-x composite samples were prepared and investigated. The structural changes of the composite (BaTiO3)x(PVC)100-x were studied as a function of BT content using FTIR, XRD and DSC measurements. Attention is paid to the tetragonality changes during composition changes.It was found that the hindrance to the PVC crystallization becomes less and less serious with the increase of BT ratio in the composite. This behavior could be attributed to the interaction between Ba+2 ions and Chlorine in the polymer. The FTIR spectra indicate a clear interaction between PVC and BaTiO3 particles as is concluded from XRD results.The Scherrer formula was used to estimate the grain size for the included BT in the (BT)x (PVC)100x composite samples. The composite samples show abnormally small tetragonality for its BT content less than unity (?/a < 1). It seems that in (BaTiO3)x(PVC)100-x composite samples, the stress that stabilized the tetragonal phase of the core regions of BT decreased, leading to lower tetragonality (c/a ratio). It seems that Tg of the composite samples increases with the increase of its BT content. Also DSC results reveal the increase of crystallization with the increase of BT content in the composite.

scholarly journals Phase Transitions and Crystal Structures of Ni(II) Complexes Determined with X-ray Powder Diffraction Data

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 106 ◽  
Author(s):  
Hisashi Konaka ◽  
Akito Sasaki
Keyword(s):  
Differential Scanning Calorimetry ◽  
Crystal Structures ◽  
Structural Changes ◽  
Original Form ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Hydrate Form ◽  
X Ray ◽  
Dsc Measurements ◽  
Crystalline Forms

Structural changes of chloride and bromide complexes, [Ni(Et2en)2(H2O)2]Cl2 (designated as 1a) and [Ni(Et2en)2]Br2 (2a), have been investigated by using simultaneous measurements of powder X-ray diffraction (XRD) and differential scanning calorimetry data under the temperature and humidity controls. The hydrate form of chloride complex 1a was transformed into an anhydrate form (1b) by heating at a temperature of 361 K. Then the 1b was reversibly returned to the original 1a by humidification at 25% relative humidity (RH) and temperature of 300 K. On the other hand, the anhydrate form of the bromide complex 2a was first transformed into a hydrate form (2b) at 30% RH and 300 K. On heating, the 2b turned to a new anhydrate form (2c) at 344 K, and then it returned to the original form 2a on further heating. In the present experiments, a series of reactions of 2a proceeded via 2c, which was newly found with the benefit of differential scanning calorimetry (DSC) measurements performed in parallel to the XRD measurements. Crystal structures of new crystalline forms of 1b, 2b, and 2c were determined from the powder XRD data.

Formation of Cu2SnSe3 from stacked elemental layers investigated by combined in situ X-ray diffraction and differential scanning calorimetry techniques

2014 ◽  
Vol 588 ◽  
pp. 254-258 ◽  
Author(s):  
Rachmat Adhi Wibowo ◽  
Stefan Moeckel ◽  
Hyesun Yoo ◽  
Astrid Hoelzing ◽  
Rainer Hock ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray
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