Details

Autor(en) / Beteiligte

• Carrasco, M.P.
• Guillem, M.C.
• Alamo, J.

Titel

Synthesis and structural study of sodium titanium phosphate-sodium tin phosphate solid solutions. II. Thermal expansion

Ist Teil von

• Materials research bulletin, 1993, Vol.28 (6), p.547-556

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

1993

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• The structure of NaTi 2(PO 4) 3 shows the space group R3&#x0304;c, whereas that of NaSn 2(PO 4) 3 presents the space group R3&#x0304; at room temperature and it undergoes a second order phase transition at 575°C from this structure to another with the space group R3&#x0304;c. Evolution of the structure of NaTi 2(PO 4) 3NaSn 2(PO 4) 3 solid solutions with temperature has been studied and temperature phase transition established for the compositions studied. Lattice thermal expansion of NaTi 2−xSn x(PO 4) 3 solid solutions with x = 1, 1.2, 1.5 has been determined from x-ray diffraction data at temperatures ranging from 26 to 1000°C. DSC and dilatometric measurements have been also carried out on these samples. The composition with x = 1.5, NaTi 0.5Sn 1.5(PO 4) 3, presents a second order phase transition at 355°C, from the phase with R3&#x0304; space group to the phase with R3&#x0304;c space group, similar to that of the compound with x = 2, NaSn 2(PO 4) 3. For the solid solution with x = 1.2, NaTi 0.8Sn 1.2(PO 4) 3, this transition seems to occur at a temperature closed to the room temperature, whereas the composition with x = 1, NaTiSn(PO 4) 3, does not show any phase transition. Thermal expansion of these solid solutions for x < 1.2 is more similar to that of NaTi 2(PO 4) 3 whereas for x > 1.2 is analogous to that of NaSn 2(PO 4) 3.