Influence of fluorides on phase relations in the molten systems MI2O-Р2О5 Mn2O3/MIIO, МI – Li, Na, K; MII – Ni, Co

Olga Petrenko, Ruslan Lavrik, Kateryna Terebilenko, Volodymir Trachevsky, Valentyna Galimova

Abstract

Addition of alkaline fluorides to molten phosphates with a composition MI2O-Р2О5-Mn2O3 and MI2O-Р2О5-MIIO (МI – Li, Na, K) gradually changes the solubility of polyvalent metals oxides and shifts the crystallization areas in the corresponding melts. The results obtained are based on solubility curves found for Mn2O3, СоО and NiO in the fluxes of MI2O-Р2О5 -MF and MI2O-Р2О5 -MF (where МI – Li, Na, K) and X-Ray diffraction, IR spectroscopy and thermal analysis. The presence of 10 and 20 % mass of fluorides provides molten polyphosphates depolymerization and yields pyro- Li2MnP2O7, K2CoP2O7, Na2CoP2O7and orthophosphates Na2Mn3(P2O7)2, NaMnPO4, NaNiPO4 single crystals growth.

Keywords

double phosphates; solubility curves; phosphate; fluoride; flux synthesis

Full Text:

PDF

DOI

https://doi.org/10.17721/fujcV7I2P104-110

References

Nagorny РG., Slobodyanik NS., Ushchapivska ТI. Lavrik RV. Double phosphates NaMn6(P3O10)(P2O7)2 and KMn6(P3O10)(P2O7)2 - advanced functional materials. Functional materials.2018; 25(4):689-694. https://doi.org/10.15407/fm25.04.689

Tanabe M, Honma T, Komatsu T. Unique crystallization behavior of sodium manganese pyrophosphate Na2MnP2O7 glass and its electrochemical properties. Journal of Asian Ceramic Societies 2017;5(2):209-215. https://doi.org/10.1016/j.jascer.2017.04.009

Shakoor RA., Kahraman R, Raja AA. Thermal Insitu Analyses of Multicomponent Pyrophosphate Cathodes Materials. Int. J. Electrochem. Sci, 2015;10:8941-8950.

Savchenko D, Kopilevich V, Voitenko L. Zinc cadmium ammine aqua monophosphate and its thermal transformations. Russian Journal of Applied Chemistry 2008;81(9):1492-1496. https://doi.org/10.1134/s1070427208090036

Kopilevich VA., Voitenko LV., Prokopchuk NM. The thermolysis of hydrated monophosphates of divalent transition metal. Vopr. Kh. i Kh.Tekn., 2018; 42(4):19 -26.

Kapshuk A, Nagornyi P, Petrenko O. Synthesis, IR spectra, and structures of double metaphosphates MNi(PO3)3 (M = Na or K). Crystallography Reports 2000;45(2):206-209. https://doi.org/10.1134/1.171164

Le S, Eng H, Navrotsky A. Energetics of cobalt phosphate frameworks: α, β, and red NaCoPO4. Journal of Solid State Chemistry 2006;179(12):3731-3738. https://doi.org/10.1016/j.jssc.2006.08.007

Stefanidis T, Nord A. Structure studies of thortveitite-like dimanganese diphosphate, Mn2P2O7. Acta Crystallographica Section C Crystal Structure Communications 1984;40(12):1995-1999. https://doi.org/10.1107/s0108270184010374

Sale M, Avdeev M, Mohamed Z, Ling C, Barpanda P. Magnetic structure and properties of centrosymmetric twisted-melilite K2CoP2O7. Dalton Transactions 2017;46(19):6409-6416. https://doi.org/10.1039/c7dt00978j

Ogorodnyk I, Zatovsky I, Slobodyanik N, Baumer V, Shishkin O. Synthesis, structure and magnetic properties of new phosphates K2Mn0.5Ti1.5(PO4)3 and K2Co0.5Ti1.5(PO4)3 with the langbeinite structure. Journal of Solid State Chemistry 2006;179(11):3461-3466. https://doi.org/10.1016/j.jssc.2006.07.015

Ogorodnyk I, Zatovsky I, Baumer V, Slobodyanik N, Shishkin O, Vorona I. Mn3+ stabilization in complex phosphate–fluoride fluxes and its incorporation into langbeinite framework. Journal of Solid State Chemistry 2007;180(10):2838-2844. https://doi.org/10.1016/j.jssc.2007.07.022