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Investigation of Phase Equilibria in the System Nd2O3–Na2O–P2O5: The Partial System NdPO4–Na3PO4–Na4P2O7

Znamierowska T., Bandrowski Sz.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 4

485-492

EN

The NdPO4–Na3PO4–Na4P2O7 portion of the oxide Nd2O3–Na2O–P2O5 system was investigated using thermoanalytical, X-ray powder diffraction and light microscopy techniques, and its phase diagram has been proposed. In the composition range of interest one ternary compound occurs, Na3Nd(PO4)2, which melts incongruently at 1485C and exhibits a polymorphic transition at about 1040C. Two subsystems: NdPO4–Na4P2O7 and Na3Nd(PO4)2–Na4P2O7, which are quasi-binary only in the subsolidus regions, i.e. 944C and 967C, respectively, have been found. It has been shown that a ternary peritectic (tP = 967C) and a ternary eutectic (t = 961C) occur in the quasi-ternary NdPO4–Na3PO4–Na4P2O7 system.

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Investigation of Phase Equilibria in the System Nd2O3–Na2O–P2O5. Quasibinary Section NdPO4–Na3PO4

Znamierowska T., Bandrowski Sz.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 10

1731-1735

EN

Quasibinary section NdPO4–Na3PO4 has been investigated by thermoanalytical methods (DTA, TG, DTG), X-ray powder diffraction and microscopy. Its phase diagram is proposed. It is found, that the parent orthophosphates react in the molar ratio 1:1 yielding an intermediate compound of Na3Nd(PO4)2. This phosphate melts incongruently at 1485C, giving NdPO4 and an Na3PO4-rich liquid. Na3Nd(PO4)2 compound is stable down to room temperature and exhibits a polymorphic transition at about 1040 graduate C.

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Study of Phase Equilibria in the System Nd2O3-Na2O-P2O5. The Partial System NdPO4-NaPO3-Nd(PO3)3

Znamierowska T., Bandrowski Sz.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 6

771-778

EN

A partial system of NdPO4-NaPO3-Nd(PO3)3 in the ternary system Nd2O3-Na2O-P2O5 was investigated and its phase diagram is proposed. Thermoanalytical methods and X-ray powder diffraction were employed. In the composition range under examination, two ternary compounds occur, which melt incongruently and have the formulae NaNd(PO3)4 (m.p. 866°C) and NaNdP2O7 (m.p. 790°C). Two quasi-binary sections, NdPO4-NaNd(PO3)4 and NaNdP2O7-NaNd(PO3)4 have been identified.

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study of Phase Equilibria in the System Nd2O3-Na2O-P2O5. The Quasi-Binary Section Nd(PO3)3-NaPO3

Znamierowska T., Bandrowski Sz.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 9

1131-1134

EN

The quasi-binary section Nd(PO3)3-NaPO3 has been investigated by thermoanalytical methods (DTA, TG, DTG) and X-ray powder diffraction and its phase diagram was proposed. It was found that initial metaphosphates react at a 1:1 molar ratio, forming the intermediate compound NaNd(PO3)4. It was confirmed, that it melts incongruently at about 866_C, giving Nd(PO3)3 and a liquid rich in NaPO3. The phosphate NaNd(PO3)4 is stable to room temperature and does not exhibit polymorphic transitions.