The Crystal Structure and Thermal Expansion
of Zinc Phosphate Li0.5Na0.15K0.85ZnP2O6.75
S. N. Volkova, *, R. S. Bubnovaa, b, M. A. Petrovaa, V. F. Popovaa, and V. V. Shilovskikhc
aGrebenshchikov Institute of Silicate Chemistry, Russian Academy of Sciences, St. Petersburg, 199034 Russia
bDepartment of Crystallography, St. Petersburg State University, St. Petersburg, 199034 Russia
cGeomodel Resource Center, St. Petersburg State University, St. Petersburg, 198504 Russia
Correspondence to: *e-mail: s.n.volkov@inbox.ru
Received 14 February, 2019
Abstract—New zinc phosphate Li0.5Na0.15K0.85ZnP2O6.75 is obtained by the crystallization of a melt and its crystal structure is determined by the single crystal X-ray diffraction data. It is monoclinic and is refined in the space group P21/n to Robs = 0.052; a = 14.609 (7) Å, b = 6.898 (5) Å, and c = 14.603 (7) Å; and β = 118.59 (5)°. The crystal structure is formed by a framework consisting of the PO4, ZnO4, and LiO4 tetrahedra. The ordering of Zn, Li, Na, and K cations and vacancies leads to the formation of a two fold superstructure. The compound belongs to the MM'ZnP2O7 structural family, the connection with which is under discussion. The thermal expansion is anisotropic, thus, α11 = 5, α22 = 29, and α33 = 9 × 10−6°C−1.
Keywords: zinc phosphate, crystal structure, thermal expansion
DOI: 10.1134/S1087659619050158