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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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Phase Equilibria in the Oxide Nd2O3-K2O-P2O5 System. The Quasibinary System NdPO4-K3PO4

Znamierowska T., Mizer D.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 12

2011-2016

EN

Phase diagram of NdPO4-K3PO4 quasibinary system has been elaborated based on investigation by thermoanalytical methods, X-ray powder diffraction, IR spectroscopy and microscopy in reflected light. One binary orthophosphate of the formula K3Nd(PO4)2 occurs in this system, and it melts incongruently at ~1415 graduate C. The compound appears in two polymorphic modifications (transformation alfa/beta-K3Nd(PO4)2 proceeds at 1150–1175 graduate C) and is stable down to room temperature.

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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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Phase Equilibria in the Ternary System Nd2O3-K2O-P2O5. The partial system NdPO4-KPO3-Nd(PO3)3

Znamierowska T., Mizer D.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 2

195-200

EN

In the ternary system Nd2O3-K2O-P2O5 a partial system NdPO4-KPO3-Nd(PO3)3 was investigated by thermoanalytical methods, X-ray powder diffraction and microscopy in reflected light and its phase diagram was proposed. In the system a double metaphosphate KNd(PO3)4 appears. The compound forms in a side system Nd(PO3)3-KPO3. It has been established that the KNd(PO3)4 and NdPO4 form a section, which is a real system only in the subsolidus region. It is found, that a ternary peritectic (tP ~ 885°C) and a ternary eutectic (tE ~ 688°C) occur in the partial system NdPO4-KPO3-Nd(PO3)3.

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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.

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Phase Equilibria in the YPO4 -- Ba3(PO4)2 System

Szuszkiewicz W., Radomińska E., Znamierowska T.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 1

23-27

EN

The binary system YPO4 -- Ba3(PO4)2 has been examined by differential thermal analysis, X-ray and microscopy in reflected light. Its phase diagram has been proposed. The initial orthophosphates react at a 1:1 and 2:1 molar ratio to give two intermediate compounds: Ba3Y(PO4)3 and Ba3Y2(PO4)4. It has been established that Ba3Y(PO4)3 melts congruently at 1950 š 20°C. Ba3Y2(PO4)4 melts incongruently at 1800 _ 20_C and is stable at high temperature only; it decomposes into YPO4 and Ba3Y(PO4)3 at about 1150_C. Double orthophosphate, Ba3Y(PO4)3, has a cubic unit cell (eulytite structure) with the parameter a = 10.4655 A.

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Phase Equilibria in the System Nd(PO3)3-KPO3

Znamierowska T., Mizer D.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 5

695-699

EN

The system Nd(PO3)3 - KPO3 has been investigated by differential thermal analysis (during heating), thermogravimetric analysis, mass spectrometry, Raman spectroscopy and X-ray powder diffraction and its phase diagram was proposed. It was discovered that initial metaphosphates react at a 1:1 molar ratio forming intermediate compound KNd(PO3)4. It was found that it melts incongruently at 854_C giving Nd(PO3)3 and a liquid rich in KPO3. Phosphate KNd(PO3)4 is stable down to room temperature and does not show any polymorphic transitions.

9

Phadse Equilibria in the System CePO4-Ba3(PO4)2

Szuszkiewicz W., Radomińska E., Znamierowska T., Wilk P.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 8

1095-1100

EN

Based on thermal investigation and X-ray powder diffraction the unknown so far phase diagram of the binary system CePO4-Ba3(PO4)2 has been elaborated. It contains an intermediate compound Ba3Ce(PO4)3, which congruently melts at about 2080 degree centigrade, is stable down to room temperature and has an eulytite structure. In the composition range given by the molar ratio of CePO4:Ba3(PO4)2 from 1:1 to 1:6 there exist solid solutions of the eulytite structure. At high temperatures there exist two binary eutectics (te1 = 1840 degree centigrade, te2 = 1600 degree centigrade).

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Phase equilibria in the system MgO-Na2)-P2)5 : the binary system Mg3(PO4)2-Na3PO4

Podhajska-Kaźmierczak T., Znamierowska T.

Polish Journal of Chemistry

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1999

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vol. 73 nr 2

279-286

EN

In the ternary system MgO-Na2O-P2O5 the binary system Mg3(PO4)2-Na3PO4 was investigated by thermal analysis, X-ray and microscopy, and its phase diagram was proposed. Three intermediate compounds occur in this system with the molar ratio Mg3(PO4)2-Na3PO4 4:1, 1:1 and 1:4, and corresponding formulas Mg4Na(PO4)3, MgNa-PO4 and MgNa4(PO4)2. The phosphate Mg4Na(PO4)3 melts incongruently at 11550C, the MgNa4(PO4)2 melts incongruently at 16550C, whereas the phosphate MgNaPO4 occurs only in the solid phase, which undergoes decomposition at 950-9600C. The polymorphism of these phosphates was investigated and temperatures of polymorphic transitions were determined.

11

Phase equilibria in a portion of the system La2O3-BaO-P2O5 rich in P2O5

Znamierowska T., Radomińska E.

Polish Journal of Chemistry

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1999

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vol. 73 nr 4

593-597

EN

The system LaPO4-Ba(PO3)2-LaP5O14, a part of the La2O3-BaO-P2O5 oxide system, has been investigated by differential thermal analysis, X-ray powder diffraction and microscopy in reflected light and its phase diagram was suggested. It was found that in the composition range under investigation, there occurs the quasi-binary section, i.e. La(PO3)3-Ba(PO3)2 only. Its phase diagram has been determined.