PHYSICAL PROPERTIES OF TELLURITE GLASSES PREPARED UNDER DIFFERENT THERMAL HISTORIES

2010 ◽  
Vol 24 (06) ◽  
pp. 527-537
Author(s):  
E. B. ARAÚJO ◽  
E. IDALGO ◽  
A. P. A. MORAES ◽  
A. G. SOUZA FILHO ◽  
J. MENDES FILHO
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Glass Transition ◽  
Tellurite Glasses ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
In Situ Crystallization ◽  
Thermal Histories

Tellurite glasses were prepared with identical 20 Li 2 O -80 TeO 2 nominal compositions but with different thermal histories. Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Raman spectroscopy techniques were used to understand the effects of the thermal histories on the thermal and structural properties of these glasses. It was observed that investigated properties depend strongly on the thermal histories. DSC results suggested that annealing immediately after quenching at temperatures around the glass transition temperature (Tg) and for longer times is favorable for producing local ordered regions in the glass without necessarily increasing the number of nuclei. XRD results revealed the crystallization of the γ- TeO 2, α- TeO 2 and α- Li 2 Te 2 O 5 phases in both studied glasses. Raman spectroscopy revealed the mestastable character of the γ- TeO 2 crystalline phase, while the α- TeO 2 and α- Li 2 Te 2 O 5 crystalline phases persisted up to the final stages of the in-situ crystallization.

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.

Low-temperature phase transition in glycine–glutaric acid co-crystals studied by single-crystal X-ray diffraction, Raman spectroscopy and differential scanning calorimetry

2012 ◽  
Vol 68 (3) ◽  
pp. 287-296 ◽  
Author(s):  
Boris A. Zakharov ◽  
Evgeniy A. Losev ◽  
Boris A. Kolesov ◽  
Valeri A. Drebushchak ◽  
Elena V. Boldyreva
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Single Crystal ◽  
Glutaric Acid ◽  
Group Symmetry ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

The occurrence of a first-order reversible phase transition in glycine–glutaric acid co-crystals at 220–230 K has been confirmed by three different techniques – single-crystal X-ray diffraction, polarized Raman spectroscopy and differential scanning calorimetry. The most interesting feature of this phase transition is that every second glutaric acid molecule changes its conformation, and this fact results in the space-group symmetry change from P21/c to P\bar 1. The topology of the hydrogen-bonded motifs remains almost the same and hydrogen bonds do not switch to other atoms, although the hydrogen bond lengths do change and some of the bonds become inequivalent.

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.

Characterization of New Cocrystals by Raman Spectroscopy, Powder X-ray Diffraction, Differential Scanning Calorimetry, and Transmission Raman Spectroscopy

2010 ◽  
Vol 10 (5) ◽  
pp. 2360-2371 ◽  
Author(s):  
M. A. Elbagerma ◽  
H. G. M. Edwards ◽  
T. Munshi ◽  
M. D. Hargreaves ◽  
Pavel Matousek ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Raman

Crystallization of Bulk Zr48Nb8Cu14Ni12Be18Metallic Glass

2000 ◽  
Vol 644 ◽  
Author(s):  
Y.X. Zhuang ◽  
L. Gerward ◽  
J.Z. Jiang ◽  
J.S. Olsen ◽  
Y. Zhang ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
High Pressure ◽  
Glass Transition ◽  
High Temperature ◽  
Synchrotron Radiation ◽  
Powder Diffraction ◽  
Applied Pressure ◽  
Scanning Calorimetry ◽  
X Ray

AbstractThe crystallization of bulk Zr48Nb8Cu14Ni12Be18metallic glass has been investigated by differential scanning calorimetry (DSC) and X-ray powder diffraction. The activation energies of glass transition and crystallization for the glass obtained using Kissinger analysis from the shift of the peak temperature in the DSC curve are 470 and 235 kJ/mol, respectively. The effect of applied pressure on crystallization is studied by in situ high-pressure and high-temperature X-ray powder diffraction using synchrotron radiation. It is found that the crystallization temperature increases with pressure having a slope of 9.5 K/GPa in the range of 0-4.4 GPa.

Thermodynamic and Structural Properties of Mev Ion Beam Amorphized Silicon

1989 ◽  
Vol 157 ◽  
Author(s):  
S. Roorda ◽  
W.C. Sinke ◽  
J.M. Poate ◽  
D.C. Jacobson ◽  
P. Fuoss ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Structural Properties ◽  
Atomic Structure ◽  
Structural Relaxation ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Amorphous Si

ABSTRACTThermodynamic and structural properties of amorphous Si (a-Si), prepared by MeV 28Si+-ion implantation are investigated by differential scanning calorimetry, Raman spectroscopy and X-ray diffraction. The influence of thermal annealing below 500 °C on a-Si is investigated with these different probes. The observed changes result from structural relaxation. Raman spectroscopy and X-ray diffraction show that structural relaxation is accompanied by changes in the average atomic structure.

scholarly journals Recent Advances in Solid-State Analysis of Pharmaceuticals

2015 ◽  
Vol 2 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Syed Nasir Abbas Bukhari ◽  
Ng Shin Hwei ◽  
Ibrahim Jantan
Keyword(s):  
Electron Microscopy ◽  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Solid State ◽  
Magnetic Resonance ◽  
Spatial Resolution ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Current analytical techniques for characterizing solid-state pharmaceuticals include powder x-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, infrared spectroscopy, Raman spectroscopy, electron microscopy and nuclear magnetic resonance. Powder x-ray diffraction and differential scanning calorimetry are mainstream techniques but they lack spatial resolution. Scanning electron microscopy and micro-Raman spectroscopy provide good chemical and optical characterization but they are not capable of analysing very small nanoparticles. Transmission electron microscopy and nano-thermal analysis can provide explicit characterization of nanoparticles but they are invasive. Nuclear magnetic resonance offers good spatial resolution but its use is mainly limited by poor sensitivity and high costs. In view of the many challenges posed by existing methods, new and novel techniques are being continually researched and developed to cater to the growing number of solid formulations in the pipeline and in the market. Some of the recent advances attained in the solid-state analysis of pharmaceutical are summarized in this review article.

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.

Sign in / Sign up

Export Citation Format

Share Document