Abstract—Crystalline Pb0.5 +xMgxZr2 –x(PO4)3 (x = 0, 0.5) phosphates of NaZr2(PO4)3 (NZP) structural type were synthesized. The heat capacity of Pb0.5Zr2(PO4)3 was measured by adiabatic vacuum and differential scanning calorimetry (DSC) within the temperature range 8–660 K. The studied phosphates were found to experience a reversible phase transition in the region 256–426 K. According to the results of Rietveld structural study, this transition occurred due to an increase in disorder of lead cation positions in cavities of the NZP structure. The measurements of PbMg0.5Zr1.5(PO4)3 heat capacity in the temperature range 195–660 K showed that it experienced a similar phase transition at 255–315 K. Based on the measured experimental data, the thermodynamic functions of Pb0.5Zr2(PO4)3, such as \(C_{p}^{0}(T),\) [H0(T) – H0(0)], S0(T), and [G0(T) – H0(0)] were calculated for the temperature range 0–660 K. The standard formation enthalpy of Pb0.5Zr2(PO4)3 was determined at 298.15 K.
Similar content being viewed by others
REFERENCES
M. I. Kimpa, M. Z. H. Mayzan, J. A. Yabagi, et al., IOP Conf. Ser.: Earth Env. Sci. 140, 012 156 (2018). https://doi.org/10.1088/1755-1315/140/1/012156
L. Small, J. Wheeler, J. Ihlefeld, et al., J. Mater. Chem. A 6, 9691 (2018). https://doi.org/10.1039/C7TA09924J
V. I. Pet’kov, Russ. Chem. Rev. 81, 606 (2012). https://doi.org/10.1070/RC2012v081n07ABEH004243
B. E. Scheetz, D. K. Agrawal, E. Breval, and R. Roy, Waste Manag. 14, 489 (1994).
V. Pet’kov, E. Asabina, V. Loshkarev, and M. Sukhanov, J. Nucl. Mater. 471, 122 (2016). https://doi.org/10.1016/j.jnucmat.2016.01.016
E. Asabina, V. Pet’kov, P. Mayorov, et al., Pure Appl. Chem. 89, 523 (2017). https://doi.org/10.1515/pac-2016-1005
V. I. Pet’kov, V. S. Kurazhkovskaya, A. I. Orlova, and M. L. Spiridonova, Crystallogr. Rep. 47, 736 (2002). https://doi.org/10.1134/1.1509386
H. M. Rietveld, Acta Crystallogr. 22, 151 (1967).
Y. I. Kim and F. Izumi, J. Ceram. Soc. Jpn. 102, 401 (1994).
V. M. Malyshev, G. A. Mil’ner, E. L. Sorokin, et al., Pribory Tekh. Eksp. 6, 195 (1985).
R. M. Varushchenko, A. I. Druzhinina, and E. L. Sorkin, J. Chem. Thermodyn. 29, 623 (1997).
G. W. H. Hohne, W. F. Hemminger, and H. F. Flammersheim, Differential Scanning Calorimetry (Springer, Berlin/Heidelberg, 2003).
V. A. Drebushchak, J. Therm. Anal. Calorim. 79, 213 (2005).
A. Mouline, M. Alami, R. Brochu, et al., J. Solid State Chem. 152, 453 (2000). https://doi.org/10.1006/jssc.2000.8711
S. A. Larregola, J. A. Alonso, J. C. Pedregosa, et al., Dalton Trans., No. 28, 5453 (2009). https://doi.org/10.1039/B821688F
S. A. Larregola, J. A. Alonso, M. Alguero, et al., Dalton Trans. 39, 5159 (2010). https://doi.org/10.1039/C0DT00079E
T. S. Yakubov, Dokl. Akad. Nauk SSSR 310, 145 (1990).
A. D. Izotov, O. V. Shebershneva, and K. S. Gavrichev, Proceedings of the All-Russia Conference on Thermal Analysis and Calorimetry, Kazan, 1996 (Kazan, 1996), p. 200.
V. V. Tarasov, Zh. Fiz. Khim. 24, 111 (1950).
V. V. Tarasov and G. A. Yunitskii, Zh. Fiz. Khim. 39, 2077 (1965).
CODATA Key Values for Thermodynamics, Ed. by J. D. Cox, D. D. Wagman, and V. A. Medvedev (New York, 1984).
Thermal Constants of Materials, Ed. by V. P. Glushko (Nauka, Moscow, 1965–1981) [in Russian].
Funding
This work was supported by the Russian Foundation for Basic Research (project nos. 19-33-90075 and 18-29-12063) and by the Ministry of Science and Higher Education of the Russian Federation (state assignment no. 4.8337.2017/BCh).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
The authors declare that they have no conflict of interests.
Additional information
Translated by E. Glushachenkova
Rights and permissions
About this article
Cite this article
Mayorov, P.A., Asabina, E.A., Pet’kov, V.I. et al. Pb0.5 + xMgxZr2 – x(PO4)3(x = 0, 0.5) Phosphates: Structure and Thermodynamic Properties. Russ. J. Inorg. Chem. 65, 711–719 (2020). https://doi.org/10.1134/S0036023620050137
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0036023620050137