scholarly journals Crystal structure and in situ decomposition of Eu(BH4)2 and Sm(BH4)2

2015 ◽  
Vol 3 (2) ◽  
pp. 691-698 ◽  
Author(s):  
Terry D. Humphries ◽  
Morten B. Ley ◽  
Christoph Frommen ◽  
Keelie T. Munroe ◽  
Torben R. Jensen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Crystal Structures ◽  
Analysis Techniques ◽  
In Situ Decomposition ◽  
Thermal Analysis Techniques

Synthesis of halide free RE(BH4)2 (RE = Eu, Sm) complexes are detailed. Their crystal structures have been determined and thermal decomposition pathways studied by in situ SR-PXD and thermal analysis techniques.

Crystal/Glass Phase Change in KSb5S8Studied through Thermal Analysis Techniques

2004 ◽  
Vol 16 (10) ◽  
pp. 1932-1937 ◽  
Author(s):  
K. Chrissafis ◽  
Theodora Kyratsi ◽  
K. M. Paraskevopoulos ◽  
Mercouri G. Kanatzidis
Keyword(s):  
Thermal Analysis ◽  
Phase Change ◽  
Glass Phase ◽  
Crystal Glass ◽  
Analysis Techniques ◽  
Thermal Analysis Techniques

scholarly journals Characterization of poled and non-poled β-PVDF films using thermal analysis techniques

2004 ◽  
Vol 424 (1-2) ◽  
pp. 201-207 ◽  
Author(s):  
V. Sencadas ◽  
S. Lanceros-Méndez ◽  
J.F. Mano
Keyword(s):  
Thermal Analysis ◽  
Analysis Techniques ◽  
Thermal Analysis Techniques

Can We Trust on the Thermal Analysis of Metal Organic Powders for thin film preparation?

2012 ◽  
Vol 1449 ◽  
Author(s):  
Jordi Farjas ◽  
Daniel Sanchez-Rodriguez ◽  
Hichem Eloussifi ◽  
Raul Cruz Hidalgo ◽  
Pere Roura ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Analysis ◽  
Thermal Analyses ◽  
Heat And Mass Transport ◽  
Analysis Techniques ◽  
Thin Film Preparation ◽  
Metal Organic ◽  
Organic Precursors ◽  
Film Preparation ◽  
Thermal Analysis Techniques

ABSTRACTThermal analysis techniques are routinely applied to characterize the thermal behavior of metal organic precursors used for oxide film preparation. Since the mass of films is very low, researchers do their thermal analyses on powders and consider that the results are representative of films. We will show here that, in general, this assumption is not true. Several examples involving precursors of YBa2Cu3O7-x (Ba and Y trifluoroacetates and Ba propionate) will serve to appreciate that films can behave very differently than powders due to their enhanced heat and mass transport paths. Ultimately, we will demonstrate that, in some cases, relying on powders thermal analysis may lead to erroneous conclusions.

scholarly journals Heat transfer simulation of the cure of thermoplastic particle interleaf carbon fibre epoxy prepregs

2018 ◽  
Vol 53 (15) ◽  
pp. 2053-2064 ◽  
Author(s):  
Tassos Mesogitis ◽  
James Kratz ◽  
Alex A Skordos
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Sensitivity Study ◽  
Process Models ◽  
Analysis Techniques ◽  
New Class ◽  
Thermosetting Polymers ◽  
Heat Transfer Simulation ◽  
Thermal Analysis Techniques ◽  
Semi Empirical

Thermochemical properties are needed to develop process models and define suitable cure cycles to convert thermosetting polymers into rigid glassy materials. Uncertainty surrounding the suitability of thermal analysis techniques and semi-empirical models developed for conventional composite materials has been raised for the new class of particle interleaf materials. This paper describes kinetics, conductivity, heat capacity and glass transition temperature measurements of HexPly® M21 particle interleaf material. Thermal models describing conventional, non-particle epoxy systems were fit to the data and validated through a thick-section cure. Results from curing experiments agree with heat transfer simulation predictions, indicating that established thermal analysis techniques and models can describe polymerisation and evolving material properties during processing of a material representing the class of interleaf toughened systems. A sensitivity study showed time savings up to about 20%, and associated energy-efficiency-productivity benefits can be achieved by using cure simulation for particle interleaf materials.

Characterization of Sol Gel Prepared KTN Thin Films and Powders by Raman, XRD, and Thermal Analysis Techniques.

2002 ◽  
Vol 718 ◽  
Author(s):  
A.A. Savvinov ◽  
S.B. Majumder ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Thermal Analysis ◽  
Sol Gel ◽  
Dynamic Effect ◽  
Orthorhombic Phase ◽  
Analysis Techniques ◽  
Perovskite Materials ◽  
Wide Range ◽  
Thermal Analysis Techniques ◽  
And Inversion

AbstractThe renewed interest in KTa1-xNbxO (KTN) mixed perovskite materials is connected with their remarkable dielectric properties in the dilute compositions. KTN thin films with x = 0.35 have been prepared on different substrates by sol-gel technique as well as a set of powders with x = 0, 0.05, 0.1, 0.25, 0.48, 0.65, 0.75, and 1. Properties of the material change drastically with the change of x, because of relaxation of both translational and inversion symmetry due to a static disorder in the Nb distribution and the dynamic effect of a precursor ferroelectric order above Tc. Special attention was paid to the characteristic feature of coupling of the single-phonon state to a two-acoustic-phonon feature through anharmonic terms in the potential function as well as behavior of the TO3 mode which becomes a narrow peak of the first-order scattering in the tetragonal ferroelectric phase and shows a tendency to split below Tc2 in the orthorhombic phase. The wide range of x allows better understanding of dynamic processes in the KTN bulk materials which in turn helps in the studies of thin films. The above mentioned materials were studied using Raman scattering, XRD, and thermal analysis techniques.

On the dimorphism of Pr6Mo10O39

2017 ◽  
Vol 72 (11) ◽  
pp. 765-774
Author(s):  
Daniel Rudolph ◽  
Sonja Laufer ◽  
Ingo Hartenbach
Keyword(s):  
Crystal Structure ◽  
Thermal Decomposition ◽  
Single Crystals ◽  
Main Product ◽  
Molar Ratio ◽  
Coordination Environment ◽  
Space Group ◽  
Coordination Numbers ◽  
Dense Modification

AbstractAttempts to synthesize Pr4Mo7O27 using Pr, Pr6O11 and MoO3 in a molar ratio of 8:6:77 led to a main product of scheelite-type Pr0.667[MoO4] and few single crystals of the triclinic A-type Pr6Mo10O39. The latter crystallizes in space group P1̅ (a=945.25(1), b=1058.49(2), c=1815.16(3) pm; α=104.149(1), β=95.220(1), γ=102.617(1)°, Z=2). Its crystal structure comprises six crystallographically independent Pr3+ cations, eight tetrahedral [MoO4]2− units, and one [Mo2O7]2− entity. The cations display coordination numbers of seven (1×) and eight (5×), while the [MoO4]2− tetrahedra are surrounded by five Pr3+ cations each. The [Mo2O7]2− anions exhibit a coordination environment of seven Pr3+ cations. The attempt to synthesize PrF[MoO4] using PrOF (from in situ thermal decomposition of PrF[CO3]) as reagent did not lead to the desired product but to monoclinic B-type Pr6Mo10O39. This slightly less dense modification compared to its triclinic analogue crystallizes in space group C2/c (a=1247.93(3), b=1989.68(6), c=1392.52 (4) pm, β=100.505(2)°, Z=4) with three crystallographically independent Pr3+ cations, four [MoO4]2− tetrahedra, and again one [Mo2O7]2− unit in the crystal structure. Thus, both Pr6Mo10O39 modifications are better described with the structured formula Pr6[MoO4]8[Mo2O7]. The coordination numbers around the Pr3+ cations are seven (1×) and eight (2×) while all four [MoO4]2− anions are again surrounded by five Pr3+ cations each. Six of the latter represent the coordination environment around the [Mo2O7]2− entities. Besides the thorough comparison of the crystal structures single crystal Raman spectra were recorded for both Pr6Mo10O39 phases.

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