Structural characterization of LaTi₂Al₉O₁₉

Abstract

Figure 1: The four-(black), fi ve-(white) and six-(grey) connected (4 4 .6 2)(4 6 .6 4)(4 8 .6 6 .8) network of 3 Two MOFs were prepared from zinc(II) sulphate and 1,3,5benzenetricarboxylic acid (H 3 BTRI) using the same method although the concentration of starting materials in the solvent system was varied. [Zn 6 (μ 3-(OH) 2 (BTRI) 4 (DMF) 2.5 (H 2 O) 2 ]·[Zn(H 2 O) 3 (DMF) 3 ]·3.1H 2 O [1] and [Zn 2 (HBTRI)(BTRI)(H 2 O) 3 ]·DMA·3H 2 O [2] are both anionic networks. The counter ions are located in channels in the structure. Scanning electron microscopy (SEM) reveals that 2 "self-heals" upon dehydration and rehydration. 1 demonstrates the six-and threeconnected (4.6 2)(4 2 .6 10 .8 3)-sab net while 2 demonstrates the fi ve-and three-connected (6 3)(6 10)-kdd net 2. Topological analysis allows for a simple comparison between different MOFs.

Dielectric resonators with complex crystal structures in the La2O3–Al2O3–TiO2 system for microwave applications

“…Contrary to this, eight molecules per unit cell (Z = 8) are reported by Kasunic et al for the title compound. The theoretical density of LTAO19 calculated using Z = 8 and Z = 4 are 4.37 and 2.18 g/cc, respectively [9]. Comparison with the experimental density of LTAO19 (3.96 g/cc), it can be inferred that the correct theoretical density of this material must be 4.37 g/cc with Z = 8.…”

“…Recently, LaTi 2 Al 9 O 19 ceramics were prepared through chemical route by Kasunic et al and the structural refinement is done by Rietveld analysis [9]. The structure of LaTi 2 Al 9 O 19 was further confirmed by bond valence sum calculations [9]. Although the powder diffraction pattern of La 3 [10][11][12][13][14].…”

“…La 3 Ti 5 Al 15 O 37 was reported to form as single phase material with slight amount of rutile as secondary phase. Recently, LaTi 2 Al 9 O 19 ceramics were prepared through chemical route by Kasunic et al and the structural refinement is done by Rietveld analysis [9]. The structure of LaTi 2 Al 9 O 19 was further confirmed by bond valence sum calculations [9].…”

“…LaTi 2 Al 9 O 19 and La 3 Ti 5 Al 15 O 37 ceramics were synthesized through chemical route and characterized using neutron, synchrotron and X-ray diffraction (XRD) techniques [7][8][9]. Morgan prepared LaTi 2 Al 9 O 19 compound through chemical route for better compositional homogeneity [7].…”

“…The structure consists of networks of AlO 6 and TiO 6 octahedra linked by AlO 4 tetrahedra and 12 fold coordinated La 3? ions[9,24,25].…”