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The presented work considers the influence of the hafnium and molybdenum to zirconium ratio of Ti20Ta20Nb20(HfMo)20−xZrx (where x = 0, 5, 10, 15, 20 at.%) high-entropy alloys in an as-cast state for potential biomedical applications. The current research continues with our previous results of hafnium's and molybdenum's influence on a similar chemical composition. In the presented study, the microstructure, selected mechanical properties, and corrosion resistance were investigated. The phase formation thermodynamical calculations were also applied to predict solid solution formation after solidification. The calculations predicted the presence of multi-phase, body-centred cubic phases, confirmed using X-ray diffraction and scanning electron microscopy. The chemical composition analysis showed the segregation of alloying elements. Microhardness measurements revealed a decrease in microhardness with increased zirconium content in the studied alloys. The corrosion resistance was determined in Ringer's solution to be higher than that of commercially applied biomaterials. The comparison of the obtained results with previously reported data is also presented and discussed in the presented study. [ABSTRACT FROM AUTHOR]

Herein, the feasibility of using hyperspectral imaging (HSI) for fast and non‐destructive size estimation of supported gold nanoparticles (AuNPs) is demonstrated. NPs of different sizes in the range of 2–12 nm in diameter are deposited onto silica supports with various pore structure. The NPs sizes are determined on the basis of TEM images. Data from HSI and UV–vis spectra, i.e., the location of the reflectance minimum and absorption maximum, respectively, are compared, and good agreement is obtained. Thus, it is shown that the hyperspectral camera can be an effective tool to characterize the size of gold NPs deposited on a porous supports. [ABSTRACT FROM AUTHOR]

The presented work aimed to investigate the influence of the hafnium/(zirconium and molybdenum) ratio on the microstructure, microhardness and corrosion resistance of Ti20Ta20Nb20(ZrMo)20−xHfx (where x = 0, 5, 10, 15 and 20 at.%) high entropy alloys in an as-cast state produced from elemental powder and obtained via the vacuum arc melting technique. All studied alloys contained only biocompatible elements and were chosen based on the thermodynamical calculations of phase formation predictions after solidification. Thermodynamical calculations predicted the presence of multi-phase, body-centered cubic phases, which were confirmed using X-ray diffraction and scanning electron microscopy. Segregation of alloying elements was recorded using elemental distribution maps. A decrease in microhardness with an increase in hafnium content in the studied alloys was revealed (512–482 HV1). The electrochemical measurements showed that the studied alloys exhibited a high corrosion resistance in a simulated body fluid environment (breakdown potential 4.60–5.50 V vs. SCE). [ABSTRACT FROM AUTHOR]

Elbrusite-(Zr) [Ca.sub.3]([U.sup.6+]Zr)([Fe.sup.3+.sub.2] [Fe.sup.2+])[O.sub.12], a new uranian garnet (Ia[bar.3]d, a [approximately equal to] 12.55 [Angstrom], V [approximately equal to] 1977 [[Angstrom].sup.3], Z= 8), within the complex solid solution elbmsite-kimzeyite-toturite [Ca.sub.3][(U,Zr, Sn, Ti, Sb, Sc, Nb ...).sub.2] [(Fe,Al,Si,Ti).sub.3] [O.sub.12] was discovered in spurrite zones in skarn xenoliths of the Upper Chegem caldera. The empirical formula of holotype elbrusite-(Zr) with 25.14 wt% U[O.sub.3] is [([Ca.sub.3.040][Th.sub.0.018][Y.sub.0.001]).sub.[summation]3.059] [([U.sup.6+.sub.0.658][Zr.sub.1.040][Sn.sub.0.230] [Hf.sub.0.009][Mg.sub.0.004]).sub.[summation]1.941] [([Fe.sup.3+.sub.1.575][Fe.sup.2+.sub.0.559][Al.sub.0.539] [Ti.sup.4+.sub.0.199][Si.sub.0.099][Sn.sub.0.025] [V.sup.5+.sub.0.004]).sub.[summation]3][O.sub.12]. Associated minerals are spurrite, rondorfite, wadalite, kimzeyite, perovskite, lakargiite, ellestadite-(OH), hillebrandite, afwillite, hydrocalumite, ettringite group minerals, and hydrogrossular. Elbrusite-(Zr) forms grains up to 10-15 [micro]m in size with dominant {110} and minor {211} forms. It often occurs as zones and spots within [Fe.sup.3+]-dominant kimzeyite crystals up to 20-30 [micro]m in size. The mineral is dark-brown to black with a brown streak. The density calculated on the basis of the empirical formula is 4.801 g/[cm.sup.3] The following broad bands are observed in the Raman spectra of elbrusite-(Zr): 730, 478, 273,222, and 135 [cm.sup.-1]. Elbrusite-(Zr) is radioactive and nearly completely metamict. The calculated cumulative dose ([alpha]-decay events/mg) of the studied garnets varies from 2.50 x [10.sup.14] [is equivalent to 0.04 displacement per atom (dpa)] for uranian kimzeyite (3.36 wt% U[O.sub.3]), up to 2.05 x [10.sup.15] (0.40 dpa) for elbrusite-(Zr) with 27.09 wt% U[O.sub.3]. Keywords: Elbrusite-(Zr), new garnet, uranium, solid solution, metamictization, Raman spectroscopy, EBSD, Upper Chegem caldera DOI: 10.2138/am.2010.3507

A new Sn-rich garnet, toturite [Ca.sub.3][Sn.sub.2][Fe.sub.2]Si[O.sub.12], occurs as an accessory mineral in high- temperature altered carbonate-silicate xenoliths in ignimbrite of the Upper Chegem structure in the Northern Caucasus, Kabardino-Balkaria, Russia. The empirical formula of toturite from the holotype sample is ([Ca.sub.2.989][Fe.sup.2+.sub.0.011])[summation]3 ([Sn.sup.4+.sub.1.463][Sb.sup.5+.sub.0.325][Ti.sup.4+.sub.0.193] [Zr.sub.0.013][Mg.sub.0.003][Nb.sup.5+.sub.0.002] [Cr.sub.0.001])[summation]2(Fe.sup.3+.sub.1.633][Al.sub.0.609][Si.sub. 0.552][Ti.sup.4+.sub.0.166][Fe.sup.2+.sub.0.039][V.sup.5+.sub.0.001]) [summation]3[O.sub.12]. The mineral forms thin regular growth zones and irregular spots in the [Fe.sup.3+]-dominant analog of kimzeyite. Toturite is cubic, Ia[bar.3]d, a [approximately equal to] 12.55 [Angstrom], as is confirmed by electron backscatter diffraction (EBSD) data. The strongest lines of the calculated powder diffraction pattern are [d, [Angstrom] (hkl)/]: 2.562 (422) 100, 1.677 (642) 91, 3.138 (400) 74, 4.437 (220) 67, 1.146 (10.4.2) 31, 1.046 (884) 25, 1.984 (620) 23. Raman spectra of toturite are analogous to those of kimzeyite and shows the following diagnostic bands ([cm.sup.-1]): 244, 301,494, 497, 575, 734. The association of toturite with larnite, rondorfite, wadalite, magnesioferrite, lakargiite, and cuspidine indicates a high temperature (>800 [degrees]C) of formation. The mineral name is given after the Totur River situated in Eltyubyu village, also Totur is the name of a Balkarian god. Keywords: Garnet, toturite, [Fe.sup.3+]-dominant analog of kimzeyite, Sn, Sb, Raman spectroscopy, EBSD, Lakargi Mountain, Russia DOI: 10.2138/am.2010.3421

Two new antimonian garnets--bitikleite-(SnAl) [Ca.sub.3]SbSn[Al.sub.3][O.sub.12] and bitikleite-(ZrFe) [Ca.sub.3]SbZr[Fe.sub.3][O.sub.12]--have been found as accessory minerals in the cuspidine zone of high-temperature skarns in a carbonate-silicate xenolith at the contact with ignimbrites within the Upper Chegem structure in the Northern Caucasus, Kabardino-Balkaria, Russia. The bitikleite series forms a solid solution with garnets of the kimzeyite-schorlomite and toturite type. Antimony-garnets form crystals up to 50 [micro]m across containing kimzeyite cores and thin subsequent zones of complex lakargiite-tazheranite-kimzeyite pseudomorphs after zircon. Bitikleite-(SnAl) has a = 12.5240(2) [Angstrom], V = 1964.40(3) [[Angstrom].sup.3] and bitikleite-(ZrFe) has a = 12.49 [Angstrom], V = 1948.4 [[Angstrom].sup.3] (la[bar.3]d, Z = 8). The strongest powder diffraction lines of bitikleite-(SnAl) are [d, [Angstrom] (hkl)]: 4.407 (220), 3.118 (440), 2.789 (420), 2.546 (422), 1.973 (620), 1.732 (640), 1.668 (642), and 1.396 (840). The strongest calculated powder diffraction lines of bitikleite-(ZrFe) are [d, [Angstrom] (hkl)]: 4.416 (220), 3.123 (440), 2.793 (420), 2.550 (422), 1.975 (620), 1.732 (640), 1.669 (642), and 1.396 (840). The Raman spectra of bitikleite garnets are similar to the spectra of kimzeyite and toturite. Larnite, rondorfite, wadalite, magnesioferrite, tazheranite, lakargiite, kimzeyite, and toturite associated with bitikleite garnets are typical of high-temperature (>800[degrees]C) formation. Keywords: Bitikleite-(SnAl), bitikleite-(ZrFe), new garnet, antimony, solid solution, single-crystal diffraction, Raman spectroscopy, Caucasus DOI: 10.2138/am.2010.3458

Priscillagrewite-(Y), ideally (Ca2Y)Zr2Al3O12 (Ia3̅̅d, a = 12.50 Å, V = 1953.13 Å3, Z = 8), a new member of the garnet supergroup and bitikleite group, was discovered in a fluorapatite layer (meta-phosphorite) hosted by varicolored spurrite marble in the Daba- Siwaqa area of the Transjordan plateau south of Amman, central Jordan. The Daba-Siwaqa area is the largest field of the Hatrurim Complex pyrometamorphic rocks distributed along the rift of the Dead Sea. Priscillagrewite-(Y) and other accessory minerals (such as members of the brownmillerite- srebrodolskite series, fluormayenite, lakargiite, baghdadite, hematite, sphalerite, zincite, garnet of the andradite-grossular series, tululite, vapnikite, minerals of the lime-monteponite series and members of the magnesiochromite-zincochromite series, cuprite, and Y-bearing and Y-free perovskite) are distributed irregularly in varicolored spurrite marble. The empirical formula of priscillagrewite-(Y), based on 12 O atoms, is C a 2.19 Y 0.65 C e 0.03 3 + N d 0.03 3 + G d d 0.02 3 + D y 0.02 3 + $\left(\mathrm{Ca}_{2.19} \mathrm{Y}_{0.65} \mathrm{Ce}_{0.03}^{3+} \mathrm{Nd}_{0.03}^{3+} \mathrm{Gdd}_{0.02}^{3+} \mathrm{Dy}_{0.02}^{3+}\right.$ E r 0.02 3 + Y b 0.02 3 + L a 0.01 3 + S m 0.01 3 + + Σ 3.00 Z r 1.79 T i 0.13 4 + S b 0.07 5 + U 0.01 6 + Σ 2.00 A l 1.70 F e 1.21 3 + S i 0.04 P 0.04 S + Σ 2.99 O 12. $\left.\mathrm{Er}_{0.02}^{3+} \mathrm{Y} \mathrm{b}_{0.02}^{3+} \mathrm{L} \mathrm{a}_{0.01}^{3+} \mathrm{Sm}_{0.01}^{3++}\right)_{\Sigma 3.00}\left(\mathrm{Zr}_{1.79} \mathrm{Ti}_{0.13}^{4+} \mathrm{Sb}_{0.07}^{5+} \mathrm{U}_{0.01}^{6+}\right)_{\Sigma 2.00}\left(\mathrm{Al}_{1.70} \mathrm{Fe}_{1.21}^{3+} \mathrm{S} \mathrm{i}_{0.04} \mathrm{P}_{0.04}^{\mathrm{S}+}\right)_{\Sigma 2.99} \mathrm{O}_{12}.$ A good match was obtained for electron backscatter diffraction (EBSD) patterns with a garnet model having a = 12.50 Å. The new garnet forms idiomorphic, isometric crystals up to 15 μm in size. It is transparent and has pale yellowish tinge, and its luster is vitreous. Priscillagrewite-(Y) is isotropic: n = 1.96 based on the Gladstone-Dale calculation using a = 12.50 Å and the empirical formula. The Mohs hardness is about 7–7.5. Density calculated from the empirical formula is 4.48 g/cm3. Raman spectrum of priscillagrewite-(Y) is similar to those of other minerals of the bitikleite group and contains the following bands (cm–1): 150, 163, 240, 269, 289, 328, 496, 508, 726, and 785. The strongest lines of the calculated powder diffraction data are as follows [(hkl) dhkl (I)]: (422) 2.552 (100), (642) 1.670 (96), (420) 2.795 (84), (400) 3.125 (72), (200) 4.419 (35), (640) 1.733 (32), and (1042) 1.141 (25). Priscillagrewite-(Y) is interpreted to be a relic of the high-temperature association formed in the progressive stage at the peak pyrometamorphism conditions when temperature could have reached close to 1000 °C. [ABSTRACT FROM AUTHOR]