Single crystal growth of CaMg₂(SO₄)₃ via solid‐ / gas‐phase reactions and its Nasicon‐related crystal structure

Abstract

Crystals of the double sulfate CaMg 2 (SO 4 ) 3 have been obtained by solid-state reactions of stoichiometric amounts of anhydrous CaSO 4 and MgSO 4 in sealed and evacuated silica tubes with chlorine gas as mineraliser. The crystal structure was determined from single crystal X-ray diffractometer data [ ] 2 dimers. Both types of chains are linked via corner-sharing with SO 4 tetrahedra into a threedimensional framework structure. Although the compound crystallizes in a new structure type, it is topologically related to the NaZr 2 (PO 4 ) 3 (Nasicon) structure, and a comparative discussion between both structural arrangements is given.

Structural Characteristics, Heat Capacity, and Thermal Expansion of BiFe2(PO4)3

“…Taking into account that the X-ray pattern of the sample (Figure ) contains only sharp diffraction peaks without asymmetry and also the absence of significant noise and amorphous diffuse halo, we may conclude that the studied phosphate is totally crystalline. X-ray results confirmed the phase purity of the studied phosphate (not less than 0.99 mass fraction of the main substance) and its crystallization in the structural type α-CaMg 2 (SO 4 ) 3 with hexagonal symmetry (space group P 6 3 / m , Z = 6) . The unit cell parameters of the compound are a = 1.43115(4) nm, c = 0.74311(2) nm, and V = 1.31812(8) nm 3 .…”

“…X-ray results confirmed the phase purity of the studied phosphate (not less than 0.99 mass fraction of the main substance) and its crystallization in the structural type α-CaMg 2 (SO 4 ) 3 with hexagonal symmetry (space group P6 3 /m, Z = 6). 10 The unit cell parameters of the compound are a = 1.43115(4) nm, c = 0.74311(2) nm, and V = 1.31812(8) nm 3 .…”

Novel red colour emitting Ca0.995Mg2(SO4)3:0.5Eu2+ phosphor under ultraviolet, blue, and green excitation for plant growth LEDs

“…The crystal structure of the CaMg 2 (SO 4 ) 3 compound was reported for the first time by M. Weil. [40] The Ca 0.995 Mg 2 (SO 4 ) 3 :0.5mol%Eu 2+ phosphor has a hexagonal crystal structure with a P6 atom. In the second O 2À site, O 2À atoms are connected to two equal Ca 2+ and a single S 6+ atom.…”

“…In the third O 2À site, O 2À atoms are connected to a single Mg 2+ and a single S 6+ atom. [40][41][42]…”