Solid solution phases

Single-phase solid solution of copper in aluminium... 

Differences in metallurgical structure. Grain boundaries, more reactive phases (solid solutions, intermetallic compounds, etc.). 

Thus the result is the formation of a single-phase solid solution. The insertion of additional guest species involves only a change in the overall (and thus also the local) composition of the solid solution, rather than the formation of additional phases. 

This review aims to present an account of the catalytic properties of palladium and nickel hydrides as compared with the metals themselves (or their a-phase solid solutions with hydrogen). The palladium or nickel alloys with the group lb metals, known to form /8-phase hydrides, will be included. Any attempts at commenting on the conclusions derived from experimental work by invoking the electronic structure of the systems studied will of necessity be limited by our as yet inadequate knowledge concerning the electronic structure of the singular alloys, which the hydrides undoubtedly are. 

Powder XR diffraction spectra confirm that all materials are single phase solid solutions with a cubic fluorite structure. Even when 10 mol% of the cations is substituted with dopant the original structure is retained. We used Kim s formula (28) and the corresponding ion radii (29) to estimate the concentration of dopant in the cerium oxide lattice. The calculated lattice parameters show that less dopant is present in the bulk than expected. As no other phases are present in the spectrum, we expect dopant-enriched crystal surfaces, and possibly some interstitial dopant cations. However, this kind of surface enrichment cannot be determined by XR diffraction owing to the lower ordering at the surface. 

DPP/Quinacridone Mixed Crystal Phase ( Solid Solutions ) Pigments... 

No. Total Composition Liquid Phase Solid Solution... 

The situation in the solid state is generally more complex. Several examples of binary systems were seen in which, in the solid state, a number of phases (intermediate and terminal) are formed. See for instance Figs 2.18-2.21. Both stoichiometric phases (compounds) and variable composition phases (solid solutions) may be considered and, as for their structures, both fully ordered or more or less completely disordered phases. This variety of types is characteristic for the solid alloys. After a few comments on liquid alloys, particular attention will therefore be dedicated in the following paragraphs to the description and classification of solid intermetallic phases. 

A clear example of this effect is found in the Li4 3,Al,Si04 solid solutions (Garcia, Torres-Trevino and West, 1990), scheme 1, Fig. 2.2. Single phase solid solutions form over the entire range x = 0-0.5. At X = 0, in stoichiometric Li4Si04, all the Li sites are full and the conductivity is low. As x increases, one particular set of Li sites in the crystal structure starts to empty and is completely empty at x = 0.5, i.e. at Li2.5Alo.5Si04. The effect on the ionic conductivity of this variation is dramatic, as shown in Fig. 2.3. A broad conductivity maximum occurs around x = 0.25, at which composition the mobile Li" sites are half-full (Mc = 0.5, where is the occupancy of the site by ions). To either side, the conductivity becomes very small as x 0 (n,. 1) and x -> 0.5 (tie 0) respectively. ... 

Chemical deposition is not limited to binary compounds. Ternary (and higher) compounds can be deposited by this technique. For the same reason as for the non II-VI and IV-VI compounds in Section 2.9.3, this section will suffice with a table of ternary compounds reported up to now, with two additions. The first is a brief consideration of the principles involved in the deposition of materials containing three or more elements. The second is to identify, in the table, which deposits have been clearly demonstrated to be a true single-phase solid solution rather than a mixture of two or more phases. 

Since the broadband spectrum shown in Figures 2c and 3c is quite distinct from those of the two end members, we interpret it as from a single phase solid solution of intermediate composition. This is consistent with what is known of the properties and provenance of the individual samples, and with its consistent presence in spectra for most feldspars of intermediate composition. 

The X-phase is similar to the Y-phase (see Fe-Mo-S system above). With increasing temperatures the X-phase expands its compositional range5,62 and surpasses the Y-phase solid solution width. But in contrast to the Y-phase, the reference composition of the X-phase has at all temperatures a Cu Mo ratio of 1 2. 

At this temperature the X-phase shows its maximum solid solution towards the Cu-rich portion of the system which diminishes above. However, with still increasing temperature, the X-phase solid solution width extends towards the Mo—S side, in particular towards MoS2 or sulfur, respectively. Figure 19 shows a schematic ternary T-X block diagram. To simplify the perspective drawing only a few isotherms are indicated. The extension of the whole solid solution width of the X-phase is projected on the base. Thus, the variation and the shifting of the temperature-dependent... 

Fig. 19. Schematic T-Xi -X2 diagram of the Cu-Mo-S system. Temperature stability and solid solution widths of the X-phase ( CuMo2S3) in the Cu-Mo-S system are displayed. To simplify the perspective drawing a few isotherms are indicated with a projection onto the base, demonstrating the whole compositional X-phase solid solution...

Series of experiments were performed to outline the high-temperature phase relations of the X—Y phase solid solution series5, Fig. 25. Details of the individual ternary reactions have been discussed above. Both endmembers, the X-phase and the Y-phase, stable above 594 4 °C and 535 15 °C, respectively, form a complete solid solution series of pseudo-character, ie., at low temperatures Cu + MoS2 +... 

Fig. 26. Previously synthesized homogeneous material of the quaternary X-Y-phase solid solution series (composition CuFeMo6S9), heated up to 1800 °C, and the melt regulus cooled to room temperature in less than 15 min. The figure shows relics of a darker Cu-Fe-rich sulfidic phase (approx, bornite composition) which separated from the Mo-rich sulfide. Thus, a large region of liquid immiscibility must exist throughout the quaternary system (cf. Figs. 15 and 20). Owing to some vapor loss molybdenum (white) has exsolved and remains in small droplets oriented in the sulfidic groundmass. Oil immersion, x 2500...

The thermal conductivity of a pure metal is lowered by alloying, whether the alloy formed is a single phase (solid solution) or multiphase mixture. There are several reasons for this. First, electrons are scattered by crystal imperfections and solute atoms (electron-defect scattering). Second, a substantial portion of the thermal conductivity in alloys, in contrast to that of pure metals, is by phonons, Kph (phonons are the sole contribution in electrically insulating solids) and phonons are also scattered by defects. Finally, electron-phonon interactions limit both Kei and Kp. ... 

The products of co-precipitation reactions are usually amorphous at or near room temperature. It is difficult to determine experimentally whether the as-prepared precursor is a single-phase solid solution or a multi-phase, nearly homogeneous mixture of the constituent metal hydroxides, carbonates and oxides that react to form a single phase mixed metal oxide when heated. 

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