The thermodynamic properties of rare earth metallic systems

Exploration and Development of High Entropy Alloys for Structural Applications

“…This makes microstructural control of Ni 5 Y precipitates difficult, since they form directly on solidification and cannot be re-dissolved. However, it may be possible to dissolve and subsequently nucleate and grow Ni 5 (2) uses ∆ values from [9,[12][13][14][15][16][17][18] and assessed for accuracy as described elsewhere [19]. A histogram of G AxBy values at 300 K is shown in Figure 3a.…”

“…A curve for binary, solid solution alloys (N = 2) is shown for comparison. The small, non-zero value for the N = 2 curve at T = 300 K comes from errors in the Miedema method used to estimate H mix [10] and from measurement errors in ∆ [9,[12][13][14][15][16][17][18][19].…”

Aurum and europium mixing enthalpies

“…In the case of bivalent REMs, the density of electron states near Fermi energy decreases [7]; hence, electron transfer from REM atoms to aurum atoms weakens. In this context, the abnormal magnetic properties exhibited by alloys of REMs with variable valency (Ce, Sm, Eu, Yb) with transition metals are usually associated with intermediate valency of REMs (+2 and +3 for Eu and Yb and about +3.4 for Ce) [7,11]. We noted this phenomenon earlier in analyzing the thermodynamic properties of Au-Yb [2] and Co-Ce [14] alloys.…”

“…The formation enthalpies for alloys of REMs with d-metals, including Cu, Ag, and Au, and Au, calculated using several semiempirical models [11] are much more negative than experimental ones [11]. Comparing the mixing enthalpies in the Cu-REM, Ag-REM, and Au-REM systems shows that exothermicity of ΔH substantially increases in series Cu → Ag → Au.…”

Growth rate and surfactant-assisted enhancements of rare-earth arsenide InGaAs nanocomposites for terahertz generation

“…44 In addition, enthalpies of formation for RE-Bi compounds are ∼3× less than their RE-As counterparts and are not expected to incorporate into or form nanoparticles with any remaining bismuth atoms without the incident bismuth flux while under a continuous arsenic overpressure. [49][50][51][52] Nanoparticles of LuAs with growth rates of 0.01, 0.02, and 0.07 monolayers/s (ML/s) were epitaxially embedded in a superlattice structure with depositions of LuAs repeated each period. LuAs growth rates and depositions are stated in terms of equivalent number of LuAs monolayers (MLs), as determined by reflection high energy electron diffraction (RHEED) intensity oscillations and/or HR-XRD measurements of bulk LuAs films.…”