| The main objective of this dissertation is to design and synthesize new alkali metal materials with vanadate,borate,nitrate or aluminosilicate,because the alkali metal has no d–d or f–f electron transitions and is ideal for the transmission of the deep-UV region. We have obtained a series of alkali metal materials by high-temperature solution method or slow evaporation at room temperature for the first time. In this dissertation, the crystal structures, synthesises, crystal growths, thermal analyses and properties of the above compounds were studied.1. Alkali metal cations insert in the frame of the V- O anion, which arrangement of the V–O anionic groups gain large optical anisotropy, then obtain a birefringent materials-Li Na V2O6. Li Na V2O6 crystallizes in the monoclinic system with space group C2/c, a = 10.184(2) ?, b = 9.067(2) ?, c = 5.8324(11) ?, β = 108.965(14)°. The transmittance spectrum of Li Na V2O6 shows that it has a wide transmittance range from 385 to 2500 nm. The ab initio calculations show that the birefringence of Li Na V2O6 is 0.136 at 589.3 nm. Based on the analysis of the relationship between crystal structure and linear optical properties, it is found that the large birefringence is attributed to the particular arrangement of V-O anionic groups. It has been grown with sizes up to 11 × 6 × 2 mm3 by the top-seeded growth method for the first time. In addition, IR spectroscopy, thermal analyses, and first-principles theoretical studies have also been performed on this compound.2. In this study, on the basis of the combination of mixed alkali metal and borates, systematic explorations in the Li2O–Na2O–B2O3 system have been done by us and Li Na B8O13, Li Na4B15O25 have been found. They are both in space group C2/c of the monoclinic system. Li Na B8O13 crystallizes in the monoclinic system with space group C2/c, a = 19.232(10)?, b = 6.636(4) ?, c = 17.307(9) ?, β = 113.990(5)o, Z = 8;Li Na4B15O25 Li Na B8O13 crystallizes in the monoclinic system with space group C2/c, a = 14.153(3)?, b = 12.122(2)?, c = 12.719(2)?, β = 105.237(13)o, Z = 4. In terms of structure, B atoms are coordinated to either three O atoms to form planar [BO3] triangles, or four O atoms to form [BO4] tetrahedra. A notable feature in the structure of Li Na B8O13 is that B8O16 is the fundamental building blocks, which the B-O anionic groups forming three dimention framework(3D) by the vertex-sharing. Li Na4B15O25 fundamental building block is B15O30, by via sharing common corners to form a complicated 3D networks. The IR spectra also confirm the existence of the BO3 triangles and BO4 tetrahedra. UV–Vis–NIR diffuse reflectance spectra of two compounds show that their UV cutoff edge are near 200 nm.3. On the basis of the combination of alkali metal nitrate and rare-earth element, the new crystal of Na4La2(NO3)10.2H2 O has been obtained by slow evaporation at room temperature and it has been grown with sizes up to 3 × 2 × 1 mm3 for the first time. It crystallizes in the monoclinic system with space group P2/c, with a = 21.49(2), b = 7.949(9), c = 15.222(17) ?, β = 90.696(13)°. After structural analyses, it can be described two types of Na On(n=7, 8) polyhedra, La O12 polyhedra and NO3 triangle groups via sharing common edges-or-corners to form a complicated 3D networks. The UV–Vis–NIR transmittance spectrum shows that it UV cutoff edge is at 295 nm.4. On the basis of the combination of mixed alkali metal and aluminosilicate, we explorae in the Li2 O – Al2O3 – Si2 O system and obtain a new compound δ-Li Al Si O4. It crystallizes in the orthorhombic system with space group Pnma. The structural is composed of Si O4 tetrahedra, Al O4 tetrahedra,Li O4 tetrahedra to form a 3D framework by the vertex-sharing. More interestingly, δ-Li Al Si O4 has a structure that resembles hexagonal diamond along c-axis. |
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