Thermodynamic and thermochemical characteristics of holmium silicides

详细信息

下载全文

推荐本文 |

• 作者：L. V. Goncharuk (1)
  V. R. Sidorko (1) dep6@ipms.kiev.ua
  N. P. Gorbachuk (1)
  M. V. Bulanova (1)
• 关键词：Gibbs energy of formation &#8211 ; enthalpy of formation &#8211 ; entropy of formation &#8211 ; enthalpy &#8211 ; heat capacity &#8211 ; entropy &#8211 ; reduced Gibbs energy &#8211 ; holmium silicides
• 刊名：Powder Metallurgy and Metal Ceramics
• 出版时间：October 2011
• 出版年：2011
• 期刊代码：27_10681302
• 类别：ph
• 卷：50
• 期：7-8
• 页码：528-537
• 数据来源：sp

摘要

The Gibbs free energy, enthalpy, and entropy of formation of holmium silicides HoSi_2–a (HoSi_1.82), HoSi_2–b (HoSi_1.67), Ho₃Si₄, HoSi, HoSi_1–x (HoSi_0.98), Ho₅Si₄, and Ho₅Si₃ are determined by the electromotive force method. The heat capacity and enthalpy of HoSi_1.67 in the temperature range 55–2007 K are measured with adiabatic and mixing calorimetry. The enthalpy and entropy of α → β polymorphic transformation and melting of HoSi_1.67 are established. Temperature dependences of the heat capacity, enthalpy, and entropy of HoSi and Ho₅Si₃ are evaluated based on the behavior of heat capacity of mono- and lower silicides of rare-earth metals and their melting enthalpies in the series from La to Lu.