Use of dynamic electron scattering for studying the position of oxygen atoms in simple metal oxide

1986 ◽  
Vol 20 (3) ◽  
pp. 195-201 ◽  
Author(s):  
R. Guan ◽  
H. Hashimoto ◽  
K.H. Kuo
2020 ◽  
Vol 8 (36) ◽  
pp. 19011-19021
Author(s):  
Gizelle I. Almerindo ◽  
Suelen C. Buratto ◽  
Eduardo H. Wanderlind ◽  
Lucas M. Nicolazi ◽  
Patrícia Sangaletti ◽  
...  

Optimization of the catalytic detoxification of a toxic organophosphorus biocide employing a simple metal oxide.


2018 ◽  
pp. 1800504
Author(s):  
Gowoon Kim ◽  
Yu‐Qiao Zhang ◽  
Taewon Min ◽  
Hoyoung Suh ◽  
Jae Hyuck Jang ◽  
...  

RSC Advances ◽  
2014 ◽  
Vol 4 (27) ◽  
pp. 14149-14156 ◽  
Author(s):  
Michael T. Kessler ◽  
Maria K. Hentschel ◽  
Christina Heinrichs ◽  
Stefan Roitsch ◽  
Martin H. G. Prechtl

Herein we present a general approach to metal and metal oxide nanoparticles using simple metal salts as starting materials.


1982 ◽  
Vol 60 (5) ◽  
pp. 693-702 ◽  
Author(s):  
Nathan Wisbr

The temperature-dependent part of the electrical resistivity ρ(T) of a metal consists of the sum of two terms, one term being due to electron–phonon scattering ρcp(T) and the other term being due to electron–electron scattering ρcc(T). One may write[Formula: see text]where θD, is the Debye temperature of the metal and the coefficients C and A give the magnitudes of ρcp(T) and ρcc(T), respectively. For a metal whose electrical resistivity exhibits "simple" behavior, it had been expected that the measured data for ρ(T) would have the following properties. (i) The function f(T/θD) should approach (T/θD) for [Formula: see text]. (ii) The magnitude of the coefficient C should be the same, or nearly so, for all measured samples. (iii) The magnitude of the coefficient A should be the same, or nearly so, for all measured samples.The low-temperature ρexpt(T) data for potassium, which has by now been measured for many samples, exhibit none of these three properties. A discussion will be presented of the reasons for this "non-simple" behavior of ρexpt(T) for potassium.


1971 ◽  
Vol 49 (13) ◽  
pp. 2310-2314 ◽  
Author(s):  
D. C. Bradley ◽  
J. W. Lorimer ◽  
C. Prevedorou-Demas

Tris(trimethylsilyloxy)aluminum, [Al(OSiMe3)3]2, was hydrolyzed under controlled conditions in dioxane at 25 °C. The soluble initial products [AlOx(OH)z(OSiMe3)3−2x−z]n, with x = 0.03–0.65, underwent disproportionation when heated at 120–150 °C under vacuum to give final products with x = 0.8–1.1. Molecular weights were determined by cryoscopy in cyclohexane, and the linear dependence of 1/n on x was combined with an extension of the theory of regular polymer series to show that the number of OH groups, z, was small compared to the number of bridging oxygen atoms, x, per Al atom. The initial products consist of dimeric units, each linked to an adjacent unit by one or two oxygen bridges between aluminum atoms. The degree of polymerization is 1 to 4, based on the dimer unit. The final products have much higher degrees of polymerization (10–40, based on the dimer), and appear to contain a higher proportion of Al—O—Al bridges.


As part of a general programme of research on the nature of inorganic melts, a study has been made of the manner in which sulphur is held in liquid silicates and aluminates. Mixtures of CaO-SiO 2 , MgO-SiO 2 , FeO-SiO 2 , CaO-Al 2 O 3 and CaO-SiO 2 -Al 2 O 3 have been brought into equilibrium, at temperatures between 1350 and 1650°C, with gas phases made by mixing H 2 , CO 2 and SO 2 at room temperature. It has been shown that, when p O 2 is less than about 10 –5 atm, a sulphur atom can only enter the melt by displacing a suitable oxygen atom. The sulphur is then held in the slag entirely as sulphide, its concentration being controlled by the general equilibrium, ½S 2 + (O)melt = ½O 2 + (S)melt. When p O 2 is greater than about 10 -3 atm, the sulphur is held as sulphate and the corresponding equilibrium is ½S 2 + 3/2O 2 + (O)melt = (SO 4 )melt∙ In the binary silicate melts there must be three kinds of oxygen atoms present: those bonded to two silicon atoms, those bonded to one silicon and those unattached to silicon. Their proportions are presumably connected by an equilibrium of the type O 2– + ⋮ Si-O-Si ⋮ = 2(⋮ Si-O¯). From the manner in which both the sulphide and sulphate equilibria depend upon the proportions of metal oxide present, it appears that only the oxygen atoms which are unattached to silicon are of importance so far as these equilibria are concerned. The potential capacity of a melt to hold sulphur as sulphide is expressed as its sulphide capacity C s = (wt. % S) ( p O 2 ) ½ /( p s 2 ) ½ . For binary silicate and aluminate melts there is a close parallelism between the value of this capacity and the activity of the basic metal oxide. The activity coefficients for CaS have been found to be the same as for CaSO 4 and approximately constant in CaO-SiO 2 mixtures. The sulphide equilibrium results have been used to improve the free energy of formation curve for the formation of CaO-SiO 2 melts, and to construct a similar curve for CaO-Al 2 O 3 melts. The temperature coefficient of the sulphide capacity for CaO-SiO 2 melts has been combined with other data and used to extend the heat of formation curve for CaO-SiO 2 melts. The sulphur capacities, and presumably the lime activities, of the ternary melts CaO-SiO 2 -Al 2 O 3 , have been shown to be a maximum at compositions for which the molar proportions of SiO 2 and Al 2 O 3 are equal; this behaviour would be expected because the energy of interaction of SiO 2 and Al 2 O 3 is much greater than that of either CaO and SiO 2 or CaO and Al 2 O 3 . It follows the pattern established for FeO activity coefficients in CaO-SiO 2 and CaO-P 2 O 5 melts, these rising to a maximum at CaO : SiO 2 and CaO; P 2 O 5 molar ratios of 2:1 and 3:1 respectively.


2011 ◽  
Vol 99 (11) ◽  
pp. 112109 ◽  
Author(s):  
H.-S. Lan ◽  
Y.-T. Chen ◽  
William Hsu ◽  
H.-C. Chang ◽  
J.-Y. Lin ◽  
...  

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