Single crystal growth and structural characterization of four complex uranium oxides: CaUO4, β-Ca3UO6, K4CaU3O12, and K4SrU3O12

Single crystal growth and structural characterization of ternary transition-metal uranium oxides: MnUO4, FeUO4, and NiU2O6

“…Single crystals of uranium containing oxides have been grown by a variety of methods, including solid-state reactions [8,, hydrothermal [6][7][8][9][10][11][12], chemical vapor transport [1][2][3][4][5], and flux methods [15,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50]. Most of the crystals reported to date were obtained from solid-state reactions, which require very high temperatures and which work best for congruently melting solids.…”

“…The single crystal growth of complex uranium-containing oxides has garnered recent attention, due to a strong desire to understand better existing structure-property relationships. Complex uranium-containing oxides have been grown as single crystals using a variety of methods, including chemical vapor transport [1][2][3][4][5], hydrothermal synthesis [6][7][8][9][10][11][12], traditional solid-state processing [8,, and flux crystal growth [15,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50]. Much of the reported crystal growth utilized the solid-state approach, however, there are some limitations with this method.…”

“…The second most published crystal growth method for complex uranium-containing oxides is flux growth. We have explored the use of hydroxide [43,44] and carbonate fluxes [42,45,46] for the crystal growth of complex oxides, and have found that the oxidizing nature of these melts limits these fluxes to compounds containing metals in high oxidation states, such as hexavalent uranium. We have recently begun using halide fluxes to explore the crystal growth of uranium containing oxides and related materials in a redox neutral environment, [51] targeting the crystal growth of complex oxides containing uranium in reduced oxidation states.…”

New Insulating Antiferromagnetic Quaternary Iridates MLa10Ir4O24 (M = Sr, Ba)

“…Flux crystal growth is an important approach to grow single crystals of new materials212223242526. For exploratory crystal growth of new iridates, KOH and K 2 CO 3 fluxes have typically been used2728.…”

Vapnikite Ca3UO6 – a new double-perovskite mineral from pyrometamorphic larnite rocks of the Jabel Harmun, Palestinian Autonomy, Israel

“…Introduction VAPNIKITE, Ca 3 UO 6 (IMA2013-082), was discovered in pyrometamorphic larnite rocks of the Jabel (Mountain in Arabian) Harmun locality belonging to the Hatrurim Formation ('Mottled Zone'; Picard, 1931;Bentor, 1960;Gross, 1977;Vapnik et al, 2007), situated in the Judean Desert, West Bank, Palestinian Autonomy, Israel (31º46'N 35º26'E). Vapnikite (P2 1 /n, Z = 2, a = 5.739(1), b = 5.951(1), c = 8.312(1) Å , b = 90.4(1)º, V = 283.9(1) Å 3 ) is the first naturally occurring ordered double perovskite of the A 2 BB'O 6 type (A, B = Ca; B' = U 6+ ) with the synthetic analogue named b-Ca 3 UO 6 (P2 1 /n, Z = 2, a = 5.728(1), b = 5.956(1), c = 8.298(2) Å , b = 90.55(3)º, V = 283.1(1) Å 3 ; Loopstra and Rietveld, 1969;van Duivenboden and IJdo, 1986;Mitchell, 2002;Read et al, 2013). The synthetic low-temperature polymorph a-Ca 3 UO 6 is trigonal (R3 , a = 9.624(1), c = 11.388(1) Å , g = 120º, V = 913.3(1) Å 3 ; Holc and Goli, 1983).…”