Synthesis and powder XRD characterization of Al2−xInx(WO4)3 solid solutions

Phase Transition and Coefficients of Thermal Expansion in Al2−xInxW3O12 (0.2 ≤ x ≤ 1)

“…200 °C. These findings are not in line with the observations from earlier reports [12][13][14]. The inconsistencies can mostly likely be attributed to erroneous interpretation and analysis of XRPD patterns at RT [13,14].…”

“…These features have been attributed in the literature to the monoclinic system (space group 12, P2 1 /a) [17,18] or P2 1 /n (space group 14) [8,19]; therefore, the XRPD pattern for x = 1 was adjusted to the monoclinic system, which described all experimental diffraction lines very well. As such, the XRPD patterns at RT (Figure 1) suggested that AlInW 3 O 12 is monoclinic at RT and not orthorhombic, as previously proposed [13,14].…”

“…Despite the promising properties of the end members, reports on the Al 2−x In x W 3 O 12 system are scant [11][12][13][14][15]. Evans et al presented a brief report [11] of dilatometry measurements, showing near-zero to low-positive CTEs for this system in the range of 0.2 ≤ x ≤ 0.5, while Mary and Sleight [12], using the same technique, reported zero thermal expansion for the AlInW 3 O 12 phase within the temperature range between RT and 727 • C. In a more recent study, Tzvetkov et al [13] reported a Rietveld XRPD study of Al 1.5 In 0.5 W 3 O 12 and AlInW 3 O 12 , suggesting both materials were orthorhombic (space group 60, Pnca) at RT. In fact, based on visual inspection of XRPD patterns, those authors attributed the orthorhombic structure at RT to all members of the Al 2−x In x W 3 O 12 system from x = 0.2 to 1.4.…”

“…To the best of the authors' knowledge, there are no thorough non-ambient studies on this system. Furthermore, there is a lack of knowledge on CTE, phase transition and hygroscopicity within the Al 2−x In x W 3 O 12 system, and there are discrepancies in the literature [13,14] concerning the RT crystal structure of some compositions from this system. In addition, there are no comparative studies of intrinsic (XRPD) and extrinsic (dilatometry) CTE for the Al 2−x In x W 3 O 12 system, so it is not clear whether this system could be used to achieve near-zero CTE phases; therefore, the evaluation the of suitability of the Al 2−x In x W 3 O 12 (x = 0.2-1.0) system for near-zero thermal expansion materials was the main knowledge gap to be filled by the present study.…”

Structural insights intoM2O–Al2O3–WO3(M= Na, K) system by electron diffraction tomography

“…This interest stimulated the study of single-crystal materials with a broad band emission in the near-IR region. The study involved several tungstates (Nikolov et al, 2003a,b,c;Nikolov, Nikolov, Kovacheva & Peshev, 2003;Nikolov, 2004;Hermanowicz, 2006;Ivanova et al, 2007;Cavalli et al, 2008;Tzvetkov et al, 2009;Koseva et al, 2011), molybdates Wang et al, 2007Wang et al, , 2008, germanates (Bykov et al, 2005), gallate spinels (Kim et al, 2004), silicates (Avanesov et al, 1997;Chen & Boulon, 2003; Padlyak et al, ISSN 2052-5206 # 2015 International Union of Crystallography 2003; Głuchowski et al, 2009), aluminates (Gurov et al, 2008), borates (De Backer et al, 2003;Brik et al, 2007), fluorides (Torchia et al, 2002;Tanner, 2004;da Silva et al, 2006) and oxides (Kü ck et al, 2000;Patra et al, 2005). Moreover, it has been proven that Cr 3+ -doped NaAl(WO 4 ) 2 (Nikolov, 2004) and KAl(MoO 4 ) 2 (Wang et al, 2008) crystals are suitable laser hosts having high absorption, efficient pumping and broad laser emission.…”