Thermodynamic Studies on Sr5Nb4O15

Anahtar Kelimeler:

niobates

Thermodynamic Studies on Sr5Nb4O15

The SrO–Nb2O5 system, especially Sr5Nb4O15 compound is of interest for their use as an electroceramics. In this work, Sr5Nb4O15 compound was synthesized by solid-state reaction and characterised by XRD. Thermodynamic properties like heat capacity, enthalpy of formation and Gibbs energy of formation of Sr5Nb4O15 have been measured. The standard molar enthalpy of formation of Sr5Nb4O15(s) was determined using an oxide melt solution high temperature calorimeter. Based on these experimental data, a self-consistent thermodynamic function of this compound was also generated. This thermodynamic data is essential for the optimization of synthesis conditions for materials and for the evaluation of their stability under appropriate technological operating conditions.

___

  • F. Galasso, L. Katz, “Preparation and Structure of Ba5Ta4O15 and Related Compounds,” Acta. Cryst., 14, 647-651, 1961.
  • H. Sreemoolanadhan, J. Lsaac, S. Solomon, M.T. Sebastian, K.A. Jose, P. Mohanan, “Dielectric Properties of Ba5Nb4O15 Ceramic,” Phys. Status Solidi., 143, 45-49, 1995.
  • H. Sreemoolanadhan, M.T. Sebastian, P. Mohanan, “High Permittivity and Low Loss Ceramics in the BaO-SrO-Nb2O5 System,” Mater. Res. Bull., 30, 653-658, 1995.
  • G. Zhu, Z. Ci, C. Ma, Y. Shi, Y. Wang, “A Novel Red Emitting Phosphor of Eu3+ Doped TTB-type Niobate NaSr2Nb5O15 for White Leds,”. Mater. Res. Bull., 48, 1995–1998, 2013.
  • Y. Miseki, H. Kato, A. Kudo, “Water Splitting into H2 and O2 over Niobate and Titanate Photocatalysts with (111) Plane-type Layered Perovskite Structure,” Energy Environ. Sci., 2, 306–314, 2009.
  • C.D. Whiston, A.J. Smith, Double Oxides Containing Niobium or Tantalum. II. Systems involving Strontium or Barium; Acta. Cryst. 23, 82-85, 1967.
  • M. Weiden, A. Grauel, J. Norwig, S. Horn, F. Steglich, “Crystalline Structure of the Strontium Niobates Sr4Nb2O9 and Sr5Nb4O15,” J. Alloy Compd., 218, 13-16, 1995.
  • “The Materials Project. Materials Data on Sr5Nb4O15,” by Materials Project. United States: N. p., 2020. Web. doi:10.17188/1291746.
  • I.N. Jawahar, P. Mohanan, M.T. Sebastian, “A5B4O15 (A=Ba, Sr, Mg, Ca, Zn; B=Nb, Ta) microwave dielectric ceramics,” Mater. Lett., 57, 4043-4048, 2003.
  • J. R. Carruthers and M. Grasso, “Phase Equilibria Relations in the Ternary System BaO‐SrO‐Nb2O5;” J. Electrochem. Soc., 117, 1426-1430, 1970.
  • Y. Yang, Yu H Jin, “Thermodynamic Calculation of the SrO-Nb2O5 System,” J. Mater. Sci. Technol., 15, 203-207, 1999.
  • J. Leitner, I. Sipula, K. Ruzica, D. Sedmidubsky, P. Svoboda, “Heat Capacity, Enthalpy and Entropy of Strontium Niobates Sr2Nb10O27 and Sr5Nb4O15;” J. Alloys Compd., 481, 35-39, 2009.
  • S.K. Rakshit, S.C. Parida, Kristina Lilova, Alexandra Navrotsky, “Thermodynamic studies of CaLaFe11O19(s),” J. Solid State Chem., 20, 68-74, 2013.
  • T.D. Mark and E. Hille, “Cross section for single and double ionization of carbon dioxide by electron impact from threshold up to 180 eV;” J. Chem. Phys., 69, 2492-2498, 1978.
  • G.W.H. Hohne, W.F. Hemminger, H.J. Flammershein, (2003), “Differential Scanning Calorimetry,” second ed., Springer, Berlin.
  • Barin I., (1995), “Thermochemical Data of Pure Substances,” vol. I & II, 3rd ed., VCH Publishers, New York,.
  • P. Samui, B.M. Singh, H.V. Khadilkar, S.K. Rakshit, S.C. Parida; “Thermodynamic Studies on Ba3SrNb2O9 Employing Calorimeter,” Int. J. Thermodyn., 24, 50-55, 2021.
  • M.W. Chase Jr., “JANAF thermochemical tables,” fourth ed, Monograph no. 9, J. Phys. Chem. Ref. Data 311-480, 1995.
  • PCPDFWIN Version 2.2, Joint Committee on Powder Diffraction Standards, JCPDS XRD file No. 00-048-0421.
  • J. Leitner, M. Nevriva, D. Sedmidubsky, P. Vonka, “Enthalpy of formation of selected mixed oxides in a CaO–SrO–Bi2O3–Nb2O5 system,” J. Alloy Compd., 509, 4940-4943, 2011.
  • B. Joseph, A. Navrotsky, D. Joseph, “Energetics of La2-xSrxCuO4-x Solid Solutions (0.0 < x < 1.0),” J. Solid State Chem., 93, 418-429, 1991.