scholarly journals Synthesis of Two-Dimensional Nb1.33C (MXene) with Randomly Distributed Vacancies by Etching of the Quaternary Solid Solution (Nb2/3Sc1/3)2AlC MAX Phase

2018 ◽  
Vol 1 (6) ◽  
pp. 2455-2460 ◽  
Author(s):  
J. Halim ◽  
J. Palisaitis ◽  
J. Lu ◽  
J. Thörnberg ◽  
E. J. Moon ◽  
...  
Keyword(s):  
Solid Solution ◽  
Max Phase ◽  
Two Dimensional ◽  
Quaternary Solid Solution

Electron microprobe study of turquoise-group solid solutions in the Neyshabour and Meydook mines, northeast and southern Iran

2020 ◽  
Vol 58 (1) ◽  
pp. 71-83
Author(s):  
Elahe Mansouri Gandomani ◽  
Nematollah Rashidnejad-Omran ◽  
Amir Emamjomeh ◽  
Pietro Vignola ◽  
Tahereh Hashemzadeh
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Electron Microprobe ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Major Elements ◽  
Point Of View ◽  
Chemical Compositions ◽  
Light Blue ◽  
Quaternary Solid Solution

ABSTRACT Turquoise, CuAl6(PO4)4(OH)8·4H2O, belongs to the turquoise group, which consists of turquoise, chalcosiderite, aheylite, faustite, planerite, and UM1981-32-PO:FeH. In order to study turquoise-group solid solutions in samples from the Neyshabour and Meydook mines, 17 samples were selected and investigated using electron probe microanalysis. In addition, their major elements were compared in order to evaluate the feasibility of distinguishing the provenance of Persian turquoises. The electron microprobe data show that the studied samples are not constituted of pure turquoise (or any other pure endmember) and belong, from the chemical point of view, to turquoise-group solid solutions. In a turquoise–planerite–chalcosiderite–unknown mineral quaternary solid solution diagram, the chemical compositions of the analyzed samples lie along the turquoise–planerite line with minor involvement of chalcosiderite and the unknown mineral. Among light blue samples with varying hues and saturations from both studied areas, planerite is more abundant among samples from Meydook compared with samples from Neyshabour. Nevertheless, not all the light blue samples are planerite. This study demonstrates that distinguishing the deposit of origin for isochromatic blue and green turquoises, based on electron probe microanalysis method and constitutive major elements, is not possible.

scholarly journals Molecular Scaffold Growth of Two-Dimensional, Strong Interlayer-Bonding-Layered Materials

CCS Chemistry ◽  
2019 ◽  
pp. 117-127 ◽  
Author(s):  
Mengqi Zeng ◽  
Yunxu Chen ◽  
Enze Zhang ◽  
Jiaxu Li ◽  
Rafael G. Mendes ◽  
...  
Keyword(s):  
2D Materials ◽  
Layered Materials ◽  
Max Phase ◽  
Future Application ◽  
Two Dimensional ◽  
Max Phases ◽  
Molecular Scaffold ◽  
Fundamental Properties ◽  
Synthesis Strategy ◽  
Interlayer Bonding

Currently, most two-dimensional (2D) materials that are of interest to emergent applications have focused on van der Waals–layered materials (VLMs) because of the ease with which the layers can be separated (e.g., graphene). Strong interlayer-bonding-layered materials (SLMs) in general have not been thoroughly explored, and one of the most critical present issues is the huge challenge of their preparation, although their physicochemical property transformation should be richer than VLMs and deserves greater attention. MAX phases are a classical kind of SLM. However, limited to the strong interlayer bonding, their corresponding 2D counterparts have never been obtained, nor has there been investigation of their fundamental properties in the 2D limitation. Here, the authors develop a controllable bottom-up synthesis strategy for obtaining 2D SLMs single crystal through the design of a molecular scaffold with Mo 2GaC, which is a typical kind of MAX phase, as an example. The superconducting transitions of Mo 2GaC at the 2D limit are clearly inherited from the bulk, which is consistent with Berezinskii–Kosterlitz–Thouless behavior. The authors believe that their molecular scaffold strategy will allow the fabrication of other high-quality 2D SLMs single crystals, which will further expand the family of 2D materials and promote their future application.

Oxidation Behavior of MAX Phase Ti2 Al(1−x ) Sn x C Solid Solution

2013 ◽  
Vol 96 (5) ◽  
pp. 1359-1362 ◽  
Author(s):  
Guoping Bei ◽  
Birgit-Joana Pedimonte ◽  
Tobias Fey ◽  
Peter Greil
Keyword(s):  
Solid Solution ◽  
Oxidation Behavior ◽  
Max Phase

scholarly journals Electronic properties and applications of MXenes: a theoretical review

2017 ◽  
Vol 5 (10) ◽  
pp. 2488-2503 ◽  
Author(s):  
Mohammad Khazaei ◽  
Ahmad Ranjbar ◽  
Masao Arai ◽  
Taizo Sasaki ◽  
Seiji Yunoki
Keyword(s):  
Transition Metal ◽  
Electronic Properties ◽  
Materials Science ◽  
Science And Technology ◽  
Max Phase ◽  
Two Dimensional ◽  
Metal Carbides ◽  
Transition Metal Carbides ◽  
Chemical Exfoliation

The recent chemical exfoliation of layered MAX phase compounds to novel two-dimensional transition metal carbides and nitrides, the so-called MXenes, has brought a new opportunity to materials science and technology.

Electro-Synthesis of Ultrafine V2AlC MAX-Phase and Its Conversion Process towards Two-Dimensional V2CTX

2020 ◽  
Vol 167 (12) ◽  
pp. 122501
Author(s):  
Pengjie Liu ◽  
Zhuoran Hou ◽  
Mengjun Hu ◽  
Liwen Hu ◽  
Rong Tang ◽  
...  
Keyword(s):  
Conversion Process ◽  
Max Phase ◽  
Two Dimensional

A novel quaternary solid solution photo-absorber material for photoelectrochemical hydrogen generation

2015 ◽  
Vol 51 (71) ◽  
pp. 13678-13681 ◽  
Author(s):  
Tiantian Hong ◽  
Zhifeng Liu ◽  
Weiguo Yan ◽  
Bo Wang ◽  
Xueqi Zhang ◽  
...  
Keyword(s):  
Solid Solution ◽  
Hydrogen Generation ◽  
Photocurrent Density ◽  
Quaternary Solid Solution ◽  
Absorber Material ◽  
First Time

We report a novel quaternary solid solution (Ag–Cu–Sb–S or ACSS) serving as a photo-absorber material in the photoelectrochemical field for the first time, and ZnO/ACSS nanoarrays exhibited a photocurrent density of 4.45 mA cm−2.

scholarly journals Modified MAX Phase Synthesis for Environmentally Stable and Highly Conductive Ti3C2 MXene

2020 ◽  
Author(s):  
Tyler Mathis ◽  
Kathleen Maleski ◽  
Adam Goad ◽  
Asia Sarycheva ◽  
Mark Anayee ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Shelf Life ◽  
Max Phase ◽  
Two Dimensional ◽  
Ambient Conditions ◽  
Phase Synthesis ◽  
Commercial Use ◽  
Aqueous Suspensions ◽  
Resistance To Oxidation ◽  
Phase Precursor

One of the primary factors limiting further research and the commercial use of the two-dimensional (2D) MXene titanium carbide (Ti3C2), as well as MXenes in general, is the rate at which freshly made samples oxidize and degrade when stored as aqueous suspensions. Here, we show that including excess aluminum during synthesis of the Ti3AlC2 MAX phase precursor leads to the creation of Ti3AlC2 grains with improved stoichiometry and crystallinity. Ti3C2 nanosheets produced from the improved Ti3AlC2 are of higher quality, as evidenced by their increased resistance to oxidation and an increase in their electrical conductivity to 20,000 S/cm. Our results indicate that defects created during the synthesis of Ti3C2 (and by inference, other MXenes) lead to the previously observed instability. We show that by eliminating those defects results in Ti3C2 that is highly stable in aqueous solutions and in air. Aqueous suspensions of single- to few-layer Ti3C2 flakes produced from the modified Ti3AlC2 have a shelf life of over ten months, compared to one to two weeks for Ti3C2 produced from conventional Ti3AlC2, even when stored in ambient conditions. Freestanding films made from Ti3C2 suspensions stored for ten months show minimal decreases in electrical conductivity and negligible oxidation. Oxidation of the improved Ti3C2 in air initiates at temperatures that are 100-150°C higher than conventional Ti3C2. The observed improvements in both the shelf life and properties of Ti3C2 will facilitate the widespread use of this material. <br>

scholarly journals A Study of two Dimensional Metal Carbide MXene Ti3C2 Synthesis, characterization conductivity and radiation properties

2019 ◽  
Vol 56 (3) ◽  
pp. 635-640
Author(s):  
Zarrul Azwan Mohd Rasid ◽  
Mohd Firdaus Omar ◽  
Muhammad Firdaus Mohd Nazeri ◽  
Syahrul Affandi Saidi ◽  
Andrei Victor Sandu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Environmental Protection Agency ◽  
Max Phase ◽  
Two Dimensional ◽  
Metal Carbide ◽  
Data Logger ◽  
Sem Images ◽  
Radiation Level ◽  
New Family ◽  
Radiation Properties

Since the discovery of exceptional properties of graphene, a lot of researchers focused on the discovery of another nobel two-dimensional (2D) materials. Recently, an elegant exfoliation approaches was proposed as a method to synthesis a new family of transitional 2D metal carbide or nitrades of MXene from a layered MAX phase. A layered MAX phase of Ti3AlC2 was synthesized through pressureless sintering (PLS) the initial powder of 3TiH2/1.1Al/2C without preliminary dehydrogenation under argon atmosphere at 1350 oC. An elegant exfoliation approach was used to eliminates Al from its precursor to form a layered-structure of Ti3C2. In this study, thermal conductivity of MAX phase and MXene were studied using absolute axial heat flow method to measure the abilities sample to conduct heat and the data was collected using Picolog 1216 Data Logger. Electrical conductivity of these two materials was also compared by using two-point probe, due to its simplicity. Radiation properties of 2D MXene Ti3C2 was studied by using an established radon monitor, placed in closed, fabricated container. Morphological and structural properties of this 2D material were also studied using an established FESEM and XRD apparatus. SEM images shows two types of morphology which is a layer of Ti3C2 and the agglomerates Al2O3 with graphite. XRD pattern reveals three phases in this material which is a rhombohedral Al2O3, rhombohedral graphite and rhombohedral Ti3C2 phases, respectively. Thermal and electrical conductivity of MXene were proven higher than MAX phase. Radon concentration for this material for five consecutive days explains the radiation level of this material which is under the suggestion value from US Environmental Protection Agency (EPA). From this finding, it is can conveniently say that the MXene material can be promising material for electronic application.

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