Bonding Heterogeneity in Mixed-Anion Compounds Realizes Ultralow Lattice Thermal Conductivity

<p><a>Crystalline materials with intrinsically low lattice thermal conductivity (</a><i>κ</i>_lat) pave the way towards high performance in various energy applications, including thermoelectrics. Here we demonstrate a strategy to realize ultralow <i>κ</i>_lat using mixed-anion compounds. Our calculations reveal that locally distorted structures in chalcohalides MnPnS₂Cl (Pn = Sb, Bi) derives a bonding heterogeneity, which in turn causes a peak splitting of the phonon density of states. This splitting induces a large amount of scattering phase space. Consequently, <i>κ</i>_lat of MnPnS₂Cl is significantly lower than that of a single-anion sulfide CuTaS₃ with a similar crystal structure. Experimental <i>κ</i>_lat of MnPnS₂Cl takes an ultralow value of about 0.5 W m⁻¹ K⁻¹ at 300 K. Our findings will encourage the exploration of thermal transport in mixed-anion compounds, which remain a vast unexplored space, especially regarding unexpectedly low <i>κ</i>_lat in lightweight materials derived from the bonding heterogeneity.</p>

Bonding Heterogeneity in Mixed-Anion Compounds Realizes Ultralow Lattice Thermal Conductivity

<p><a>Crystalline materials with intrinsically low lattice thermal conductivity (</a><i>κ</i>_lat) pave the way towards high performance in various energy applications, including thermoelectrics. Here we demonstrate a strategy to realize ultralow <i>κ</i>_lat using mixed-anion compounds. Our calculations reveal that locally distorted structures in chalcohalides MnPnS₂Cl (Pn = Sb, Bi) derives a bonding heterogeneity, which in turn causes a peak splitting of the phonon density of states. This splitting induces a large amount of scattering phase space. Consequently, <i>κ</i>_lat of MnPnS₂Cl is significantly lower than that of a single-anion sulfide CuTaS₃ with a similar crystal structure. Experimental <i>κ</i>_lat of MnPnS₂Cl takes an ultralow value of about 0.5 W m⁻¹ K⁻¹ at 300 K. Our findings will encourage the exploration of thermal transport in mixed-anion compounds, which remain a vast unexplored space, especially regarding unexpectedly low <i>κ</i>_lat in lightweight materials derived from the bonding heterogeneity.</p>

Nanoscale compositional segregation in complex In-bearing sulfides: Results from atom probe tomography and transmission kikuchi diffraction

&lt;p&gt;Indium-bearing sphalerites from the H&amp;#228;mmerlein skarn deposit, located in the western Erzgebirge (Germany), show complex distribution patterns of major and minor elements on a micrometer to sub-micrometer scale. However, with the spatial resolution of traditional analytical methods, such as SEM-based image analysis and field emission electron probe microanalysis (FE-EPMA), many features in these spalerites cannot be resolved. It remains unclear whether Cu, In and Fe are in solid solution in the sphalerite, are concentrated in nanoparticles or form discrete phases.&lt;/p&gt;&lt;p&gt;Atom probe tomography combined with transmission kikuchi diffraction has been used to resolve both the compositional heterogeneity and the nanostructure of these complex In-Cu-Fe-sphalerites. The obtained data indicate a complex structure with micro- to nanometer sized, plate-shaped inclusions of chalcopyrite in the sphalerite. In addition, a nanometer scale In-Cu-sulfide phase forms plate-like segregations in the sphalerite. All types of segregations have similar crystal structure and record the same crystal orientation indicating that they likely formed by exsolution.&lt;/p&gt;&lt;p&gt;The results indicate that complex sulfides containing cations of more than one element as minor or major constituents may represent discrete, exsolved phases, rather than solid solutions or being concentrated in nanoparticles. This heterogeneous nature will affect the nanoscale properties of the sphalerite, which may have implications for the economic extraction of precious elements such as In, when processing these minerals for beneficiation. Furthermore these nanoscale properties will open up new perspectives on formation processes of In-Cu-Fe-sphalerites, which might be relevant for other chemically complex minerals as well.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

Isomorphous Crystals Formed by the Similar Supramolecular Motifs in Sorafenib Hydrochloride and Regorafenib Hydrochloride Salts

Sorafenib and regorafenib (or fluoro-sorafenib) are multikinase inhibitors active in the treatment of various human cancers, but their solubilities are very poor. To improve their solubilities, in this study, sorafenib hydrochloride (Sor·HCl, I) and regorafenib hydrochloride (Reg·HCl, II) have been prepared and their crystal structures were characterized. Their solubility properties in water were evaluated. Intriguingly, they are isomorphous crystal structures with the same space group and the similar unit cell dimensions, which were caused by the similar supramolecular patterns resulted by the formation of N–H···Cl− hydrogen bond instead of hydrogen bond between the protonated pyridinium cation and counterion. Moreover, the solubility properties displayed identical profiles. It may be concluded that a similar crystal structure leads to a comparable solubility profile.

Destructive testing method for specimen and crystal structure on maximum solubility

From non-destructive testing, we have found various flaws in both specimens so no method in the universe is perfect but we can rectify the defects but cannot be removed completely. From destructive testing we have found that First specimen MS (MS) sustain stress without failure due its similar crystal structure (BCC) on the other hand second specimen have failed within the lower stress range due to lack of cohesion, adhesion between the dissimilar metals MS and SS, and also both have different crystal structures BCC and FCC respectively. Thus, to gain maximum strength of weld bead, welding should be done using similar metals with maximum solubility.

Modulating single-molecule magnet behaviour of phenoxo-O bridged lanthanide(iii) dinuclear complexes by using different β-diketonate coligands

Three Dy2 complexes with similar crystal structure have been synthesized. Magnetic studies reveal that they exhibit different magnetic relaxation behaviors, originating from the different chemical environments of the center Dy3+ ions with different β-diketonate coligands.

Study on Flotation Mechanism of Separation of Potassium Feldspar from Quartz with Anion and Cation Mixed Collector

Potassium feldspar and quartz are all silicate minerals with frame structure,and have the similar crystal structure and physicochemical properties. Therefore, flotation has become the main method to separate potassium feldspar from quartz. The separation of potassium feldspar from quartz with anion and cation mixed collector was studied in the paper. The sodium oleate and sodium dodecyl benzene sulfonate were respectively used as collector agents in potassium feldspar and quartz single mineral flotation tests. The analysis of the variation of the surface properties of potash feldspar and quartz after using the collectors was conducted with infrared spectra and electrokinetic potential, followed by the mechanism of separation of potassium feldspar from quartz with anion and cation mixed collector.

Studies on the Catalytic Performance of the Nieuwland Catalyst and Anhydrous Catalyst in the Dimerization of Acetylene to Monovinylacetylene

The present work aimed to find reasons for different catalytic ability of the Nieuwland catalyst and anhydrous catalyst in dimerization of acetylene to produce Monovinylacetylene (MVA). The results showed the catalytic ions in the Nieuwland catalyst and the anhydrous catalyst were CuCl-2 and Cu2Cl-3 respectively by studies on the Cu-containing crystals recovered from corresponding catalyst. CuCl-2 in crystal A and Cu2Cl-3 in crystal B has similar crystal structure, however, Cu(Ι) in Cu2Cl-3 has higher electron density due to stronger bond energy of Cu(Ι)-Cl, which may contribute to the higher activity of the anhydrous catalyst than that of Nieuwland catalyst.

Evaluation on Combustion Properties of Nanoparticle as Fuel Additive

To improve combustion properties of fuel oils, save energy and reduce pollution, the metal nanoparticles modified by fatty acids have been prepared. The dispersion capacities of these modified nanoparticles in liquid paraffin oil were examined, and were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectrum (FTIR) . The results show they possess similar crystal structure as organic shell, and average particle diameters, which are in agreement with their excellent oil-solubilities. Moreover, the properties of the modified nanoparticles additives in boiler fuel were evaluated by means of oxygen bomb relative method as regards energy saving and residual products lowering. The results show that the efficiency of combustion and decrement of residual products for fuels were improved to different degree. Therefore, notable economic and social benefits are brought.

Structures of relevant ammonium salts in fertilizers

The crystal structures of two double salts of ammonium nitrate (AN) and ammonium sulfate (AS) are reported. The double salts 2NH4NO3·(NH4)2SO4 (2AN·AS) and 3NH4NO3·(NH4)2SO4 (3AN·AS) show a very similar crystal structure packing with alternating layers of anions and cations. The solid-state ionic distribution is controlled by an extensive hydrogen-bonding network with ammonium groups as the donors and O atoms acting as the acceptors. Crystallographic studies were conducted at both room temperature (293 K) and 100 K. Increasing the temperature involves shortening the b axis in the case of the 3AN·AS salt. Quantification of fertilizer mixtures using the Rietveld method was also carried out by means of the structural models reported in this paper for both salts.