物理化学学报 >> 1999, Vol. 15 >> Issue (07): 624-628.doi: 10.3866/PKU.WHXB19990709

研究论文 上一篇    下一篇

复合金属氧化物SrCoO3-δ氧非化学计量研究

嵇世山, 李增喜, 谭瑞琴, 陈志华, 曹立礼   

  1. 清华大学化学系 100084|天津大学化工系 300072
  • 收稿日期:1998-10-13 修回日期:1999-01-18 发布日期:1999-07-15
  • 通讯作者: 嵇世山

The Study of the Oxygen Nonstoichiometry in Oxide SrCoO3-δ

Ji Shi-Shan, Li Zeng-Xi, Tan Rui-Qin, Chen Zhi-Hua, Cao Li-Li   

  1. Department of Chemistry,Tsinghua University,Beijing 100084|Department of Chemical Engineering,Tianjin University,Tianjin 300072
  • Received:1998-10-13 Revised:1999-01-18 Published:1999-07-15
  • Contact: Ji Shi-Shan

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摘要：

 通过NH4NO3共熔法合成了SrCoO3-δ,利用XRD和差热分析对其进行了结构表征，采用精密气体测量方法研究了SrCoO3-δ在温度672－918K区间，氧气分压0.7－59.3kPa区间内氧的非化学计量及其与外界氧分压、温度的定量关系，在提出氧缺陷形成模型的基础之上，首次给出了描写SrCoO3-δ-O2体系相平衡的数学公式．并以SrFeO3-δ为例评价了该缺陷模型的普适性．测定了SrCoO3-δ-O2体系溶氧过程的焓变和熵变分别为（75.3±1.2）kJ•mol－1，（96.7±1.5）J•mol－1•K－1.

关键词: 锶钴复合氧化物, 非化学计算, 氧缺陷模型, 焓变, 熵变

Abstract:

The sample 0f SrCoO3-δ was prepared by ammonium nitrate (NH4NO3) co-melted method and the structure of which was characterized by XRD and thermal analysis. The relationship between the oxygen nonstochiometry and the oxygen pressure and temperature was studied under the conditions of temperature 672 - 918 K and the oxygen pressure 0.7 - 59. 3 kPa. The model of the oxygen deficiency formation was firstly suggested and the mathematic formula describing the phase equilibrium of the SrCoO3 -δ-O2 system was given. The general applicability of the deficiency model was evaluated for the example of SrFeO3- δ. The enthalpy change and the entropy change of the SrCoO3-δ-O2 system in the process of dissolving oxygen were measured to be (75. 3 ±1. 2) kJ•mol-1 and (96. 7 ±1. 5) J•mol-1.K-1 respectively.

Key words: Strontium cobaltate complex oxide, Nonstoichiometry, Oxygen deficiency model, Enthalpy change, Entropy change