crystal boundaries
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2021 ◽  
Vol 906 (1) ◽  
pp. 012122
Author(s):  
Marco Lezzerini ◽  
Jacopo Civita ◽  
Andrea Aquino ◽  
Stefano Pagnotta

Abstract In this work, marbles from Castagneto Carducci (Livorno province, Tuscany), which originated by contact metamorphism of the Calcare Massiccio Fm., an Early Jurassic limestone belonging to the Tuscan Sequence, were studied for determining their chemical, mineralogical and petrographic characteristics, and the main physical and mechanical properties. Forty marble samples were sampled and analysed; they are from two inactive quarries on the NW and NE slopes of the Mt. Romitorino, and from natural outcrops in the vicinity of the quarries. The analysed rocks are marbles with high calcite content (> 98% by weight). Optical microscopy observations showed Castagneto Carducci marbles generally have a heteroblastic/granoblastic texture with crystal boundaries from curved-right to lobate. The maximum grain size of the calcite crystals ranges from 0.2 mm to 0.6 mm. The determination of the main physical and mechanical properties of the analysed marbles showed that these rocks are characterised by low porosity and, in general, good physical and mechanical properties.


Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1140
Author(s):  
Miłosz Huber ◽  
Klaudia Stępniewska

Thirty-eight samples of minerals from Paleoproterozoic Layered PGE Intrusion Monchepluton, located in NE Fennoscandia, were tested. An automated computational technique was used which involved counting the sides superimposed on vectorized graphics using separated crystal boundaries. The results were obtained for olivine, orthopyroxene, clinopyroxene, and plagioclase. On this basis, an interpretation of the mineral box fractal dimension was made, along with an interpretation of its nature in the rock in which it was found. The performed calculations were applied to the sampling positions, and maps of changes in fractal dimensions were prepared. The nature of the minerals studied was correlated with the type of rocks present in Monchepluton. Then, the fractal dimensions were scaled to a percentage scale determining the mean value for the euhedral crystal as 100%, and a map was obtained representing the advancement of secondary processes after summing these data for all four investigated minerals. This method was analyzed and its advantages and limitations shown.


Solar RRL ◽  
2019 ◽  
Vol 3 (5) ◽  
pp. 1900053 ◽  
Author(s):  
Liang Kuai ◽  
Yusheng Wang ◽  
Zixiang Zhang ◽  
Yingguo Yang ◽  
Yuanshuai Qin ◽  
...  

2018 ◽  
Vol 53 ◽  
pp. 01035
Author(s):  
Shulv Zhang ◽  
Yuhang Yin ◽  
Weiling Luan ◽  
Mengke Liu

Inorganic perovskite light-emitting diodes (PeLEDs) with full coverage and compact films were realized by doping a certain amount of PEO into perovskite emitting layer. The additive PEO (Polyethylene oxide) can not only improve the coverage of films by physically filling the pin-holes of crystal boundaries but also act as a protective layer to passivate the films, which successfully reduce the rate of non-radiative recombination, and enhance photoluminescence quantum yield (PLQY) of the CsPbBr3 films. In addition, PEO can also decrease the surface roughness of the perovskite films. As a result, the addition of PEO can improve the transport capability of carriers in PeLEDs. By optimizing the concentration of PEO, a maximum external quantum efficiency (EQE) of 0.26% and brightness of 1432 cd/m2 were achieved, which is significantly improved compared with previous work. The results presented in this paper shows that the additive PEO in perovskite precursor solution paves a new way for the application in PeLEDs.


Author(s):  
Katarzyna CYRAN ◽  
Tomasz TOBOŁA ◽  
Paweł KAMIŃSKI

The paper presents the attempt to find a correlation between the content of impurities and mechanical parameters of rock salt from the LGOM. Research was carried out in three steps: uniaxial compressive strength tests, determination of the content of insoluble minerals (impurities), and observations under the microscope and Raman microspectroscopy. The research results reveal that the rock salt which is characterized by low content of insoluble minerals (0.13–2.11% wt.) shows no correlation between the mechanical properties and the content of impurities. However, it was found that mechanical properties depend on both the distribution of impurities in halite crystals and the presence of fluid inclusions and hydrocarbons along the crystal boundaries. Moreover, the distribution of anhydrite at the edges of halite crystals may influence an increase of rock salt strength. On the contrary, the presence of fluid inclusions and hydrocarbons along the halite crystal boundaries may reduce the rock salt strength.


Author(s):  
A. Shterenlikht ◽  
L. Margetts

A three-dimensional cellular automata (CA) with rectilinear layout is used in this work to create and cleave polycrystalline microstructures. Each crystal is defined by a unique randomly generated orientation tensor. Separate states for grains, grain boundaries, crack flanks and crack fronts are created. Algorithms for progressive cleavage propagation through crystals and across grain boundaries are detailed. The mesh independent cleavage criterion includes the critical cleavage stress and the length scale. Resolution of an arbitrary crystallographic plane within a 26-cell Moore neighbourhood is considered. The model is implemented in Fortran 2008 coarrays. The model gives realistic predictions of grain size and mis-orientation distributions, grain boundary topology and crack geometry. Finally, we show how the proposed CA model can be linked to a finite-element model to produce a multi-scale fracture framework.


2013 ◽  
Vol 652-654 ◽  
pp. 1119-1123
Author(s):  
Wan Wu Ding ◽  
Jiang Tao Zhu ◽  
Wen Jun Zhao ◽  
Tian Dong Xia

The regular pattern of evolution of TiC and TiAl3 during the remelting process of Al-Ti-C alloy wires was analyzed and the impact mechanism was discussed. The results show that: when the temperature of the remelting mass is at 730°C, with the increase of the heat preservation time of remelting, the degree of agglomeration of the original dispersed TiC will increase, and they are pushed toward crystal boundaries by α-Al during the solidification process, while TiAl3 will dissolve, aggregate, and grow. When the remelting temperature is at 1000°C, as the heat preservation time increases, not only the agglomeration degree of TiC increases significantly compared to that at 730 °C and the sizes and shapes of TiAl3 change significantly as well. The morphology of TiAl3 will change from being lump-and-short-rod-like to needle-and-flake-like. Before and after remelting, the Al-Ti-C alloys are both composed of TiAl3 and TiC, with no other phases formed.


2012 ◽  
Vol 602-604 ◽  
pp. 1503-1507
Author(s):  
Xia Wu ◽  
Hui Dong Yang ◽  
Ji Sen Zhang ◽  
Long Gu

The films were deposited on glass slide substrates by DC magnetron sputtering method by using a ZnO target doped with Ga2O3 of 3wt%, then annealing processing were implemented respectively under the temperature of 250 °C with the time of 0,30,60,90 and 120 minutes.Effects of sputtering on the structural and optical and electrical properties of GZO films had been investigated. The results showed that GZO films with high quality could be fabricated after vacuum-annealed. crystal face of GZO films had a good tendency of c axis. the (002) diffraction peak reached a maximum at the annealing time of 1.5 hours; at the same time ,crystal grain became larger and crystal boundaries narrow, film’s resident stress reduced to 0.5 Mpa.With the annealing time increasing, the resistivity of GZO films decreased and reached the minimum which was 9.1×10-4 Ω·cm at 1.5 hours. While the average transmittance decreased sharply after the time of 1.5 hours in visible region. Consequently, the best annealing time is 1.5 hours.


2012 ◽  
Vol 446-449 ◽  
pp. 288-292
Author(s):  
Song Yu ◽  
H D Yang ◽  
B Huang ◽  
J S Zhang

GZO transparent conductive thin films were deposited by the direct current magnetron sputtering method from a ZnO target doped with Ga2O3 of 3wt% on glass slide substrates under high pressure of argon. The effect of substrate temperature on the GZO film’s morphology, optical and electrical properties is investigated by using scanning electron microscopy (SEM), UV spectrophotometer, four point probe and Spectroscopic Ellipsometer. The results showed that GZO thin films with high quality could be fabricated under the high pressure of argon.When substrate temperature is 250°C or below, surface morphology of thin films can be significantly improved.With the increase of substrate temperature, the crystal grain become larger, the crystal boundaries narrow and become clear, and reach a best case at 250°C. At the same time, the resistivity of GZO thin films decrease and reach the minimum which is 1.099×10-3 Ω•cm at 300°C while the average transmittance increase to 90%. Consequently, the properties of morphology began to get worse with the increase of temperature above 300°C.


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