Structural manifestation of partial proton ordering and defect mobility in ice Ih

2019 ◽  
Vol 21 (16) ◽  
pp. 8264-8274 ◽  
Author(s):  
A. D. Fortes

High precision lattice-parameter measurements provide a potential roadmap to producing partially-ordered states of water ice.

1992 ◽  
Vol 180-181 ◽  
pp. 609-611
Author(s):  
G. Müller ◽  
B. Bischof ◽  
B. Alefeld

1983 ◽  
Vol 18 (1) ◽  
pp. K28-K30 ◽  
Author(s):  
S. Grosswig ◽  
W. Melle ◽  
U. Schellenberger ◽  
W. Zahorowski

2012 ◽  
Vol 68 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Martin Schmidbauer ◽  
Albert Kwasniewski ◽  
Jutta Schwarzkopf

The lattice parameters of three perovskite-related oxides have been measured with high precision at room temperature. An accuracy of the order of 10−5 has been achieved by applying a sophisticated high-resolution X-ray diffraction technique which is based on the modified Bond method. The results on cubic SrTiO3 [a = 3.905268 (98) Å], orthorhombic DyScO3 [a = 5.442417 (54), b = 5.719357 (52) and c = 7.904326 (98) Å], and orthorhombic NdGaO3 [a = 5.428410 (54), b = 5.498407 (55) and c = 7.708878 (95) Å] are discussed in view of possible systematic errors as well as non-stoichiometry in the crystals.


2016 ◽  
Vol 255 ◽  
pp. 55-60 ◽  
Author(s):  
Yissel Contreras ◽  
Pablo Mancheno-Posso ◽  
Anthony J. Muscat

Self-assembled 1-eicosanethiolate layers were deposited on the oxide-free (100) crystal planes of GaAs, In0.53Ga0.47As, and InSb to protect the surfaces. The layer prevented re-oxidation in air for 30 min on GaAs but only 8 min on In0.53Ga0.47As based on the O 1s x-ray photoelectron spectroscopy state. The layer protected InSb from reoxidation for only 4 min based on the O Auger state. Well-ordered monolayers formed on GaAs and In0.53Ga0.47As based on transmission Fourier transform infrared (FTIR) spectroscopy. A partially ordered layer was formed on InSb based on attenuated total reflection FTIR. The increased reoxidation rate of InGaAs and InSb is due to the larger lattice parameter of these surfaces and their In content, which forms weaker bonds to S, Ga, and Sb compared to Ga bonding to As and S.


Author(s):  
R. A. Ricks ◽  
Angus J. Porter

During a recent investigation concerning the growth of γ' precipitates in nickel-base superalloys it was observed that the sign of the lattice mismatch between the coherent particles and the matrix (γ) was important in determining the ease with which matrix dislocations could be incorporated into the interface to relieve coherency strains. Thus alloys with a negative misfit (ie. the γ' lattice parameter was smaller than the matrix) could lose coherency easily and γ/γ' interfaces would exhibit regularly spaced networks of dislocations, as shown in figure 1 for the case of Nimonic 115 (misfit = -0.15%). In contrast, γ' particles in alloys with a positive misfit could grow to a large size and not show any such dislocation arrangements in the interface, thus indicating that coherency had not been lost. Figure 2 depicts a large γ' precipitate in Nimonic 80A (misfit = +0.32%) showing few interfacial dislocations.


Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).


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