Journal of Inorganic Materials

• Research Paper • Previous Articles     Next Articles

Crystal Growth and TG-DTA Properties of K2Ln(NO3)5.2H2O(Ln=La, Ce, Pr, Nd, Sm)

DONG Wen-Ting; ZHANG Hong-Jie; SU Qiang   

  1. Key Laboratory of Rare Earth Chemistry and Physics; Changchun Institute of Applied Chemistry; Chinese Academy of Sciences Changchun 130022 China
  • Received:1997-11-24 Revised:1998-01-23 Published:1998-12-20 Online:1998-12-20

Abstract: Single crystals of KLnN(Ln=La, Ce, Pr, Nd, Sm) can be grown in water solution with pH≈1~2 at about 40℃. Crystals of KLnN
(Ln=La, Ce, Pr, Nd) are orthorhombic with space group Fdd2. KPrN crystal was grwon and its crystal structure was determined for the first time.
The KPrN crystal parameters obtained by the direct method are as follows: a=21.411(3)A, b=11.2210(10)A, c=12.208(2)A, Z=6, R=0.0240. The TG-DTA curves of KLnN(Ln=
La, Ce, Pr, Nd, Sm) demonstrate that the processes of dehydration , melt, irreversible phase transition and decomposition of NO-3 take place in sequence with the temperature increasing(except KCN). There are three steps in the
decomposition of NO-3 in KLnN(Ln=La, Nd, Sm) while two steps in KLnN(Ln=Ce, Pr). K2Ln(NO3)5·2H2O are formed at about 225℃
by the reaction of the starting materials of KNO3 and Ln(NO3)3·nH2O.

Key words: rare earth, potassium lanthanide nitrate hydrate, crystal growth,TG-DTA

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